It was half-past five before Holmes returned. He was bright, eager, and in excellent spirits,—a mood which in his case alternated with fits of the blackest depression.
"There is no great mystery in this matter," he said, taking the cup of tea which I had poured out for him. "The facts appear to it of only one explanation."
"What! you have solved it already?"
"Well, that would be too much to say. I have discovered a suggestive fact, that is all. It is, however, VERY suggestive. The details are still to be added. I have just found, on consulting the back files of the Times, that Major Sholto, of Upper Norword, late of the 34th Bombay Infantry, died upon the 28th of April, 1882."

"I may be very obtuse, Holmes, but I fail to see what this suggests."

"No? You surprise me. Look at it in this way, then. Captain Morstan disappears. The only person in London whom he could have visited is Major Sholto. Major Sholto denies having heard that he was in London. Four years later Sholto dies. WITHIN A WEEK OF HIS DEATH Captain Morstan's daughter receives a valuable present, which is repeated from year to year, and now culminates in a letter which describes her as a wronged woman. What wrong can it refer to except this deprivation of her father? And why should the presents begin immediately after Sholto's death, unless it is that Sholto's heir knows something of the mystery and desires to make compensation? Have you any alternative theory which will meet the facts?"

"But what a strange compensation! And how strangely made! Why, too, should he write a letter now, rather than six years ago? Again, the letter speaks of giving her justice. What justice can she have? It is too much to suppose that her father is still alive. There is no other injustice in her case that you know of."
"There are difficulties; there are certainly difficulties," said Sherlock Holmes, pensively. "But our expedition of to-night will solve them all. Ah, here is a four-wheeler, and Miss Morstan is inside. Are you all ready? Then we had better go down, for it is a little past the hour."
I picked up my hat and my heaviest stick, but I observed that Holmes took his revolver from his drawer and slipped it into his pocket. It was clear that he thought that our night's work might be a serious one.
Miss Morstan was muffled in a dark cloak, and her sensitive face was composed, but pale. She must have been more than woman if she did not feel some uneasiness at the strange enterprise upon which we were embarking, yet her self-control was perfect, and she readily answered the few additional questions which Sherlock Holmes put to her.

"Major Sholto was a very particular friend of papa's," she said. "His letters were full of allusions to the major. He and papa were in command of the troops at the Andaman Islands, so they were thrown a great deal together. By the way, a curious paper was found in papa's desk which no one could understand. I don't suppose that it is of the slightest importance, but I thought you might care to see it, so I brought it with me. It is here."

Holmes unfolded the paper carefully and smoothed it out upon his knee. He then very methodically examined it all over with his double lens.
"It is paper of native Indian manufacture," he remarked. "It has at some time been pinned to a board. The diagram upon it appears to be a plan of part of a large building with numerous halls, corridors, and ages. At one point is a small cross done in red ink, and above it is '3.37 from left,' in faded pencil-writing. In the left-hand corner is a curious hieroglyphic like four crosses in a line with their arms touching. Beside it is written, in very rough and coarse characters, 'The sign of the four,—Jonathan Small, Mahomet Singh, Abdullah Khan, Dost Akbar.' No, I confess that I do not see how this bears upon the matter. Yet it is evidently a document of importance. It has been kept carefully in a pocket-book; for the one side is as clean as the other."

"It was in his pocket-book that we found it."

"Preserve it carefully, then, Miss Morstan, for it may prove to be of use to us. I begin to suspect that this matter may turn out to be much deeper and more subtle than I at first supposed. I must reconsider my ideas." He leaned back in the cab, and I could see by his drawn brow and his vacant eye that he was thinking intently. Miss Morstan and I chatted in an undertone about our present expedition and its possible outcome, but our companion maintained his impenetrable reserve until the end of our journey.

It was a September evening, and not yet seven o'clock, but the day had been a dreary one, and a dense drizzly fog lay low upon the great city. Mud-colored clouds drooped sadly over the muddy streets. Down the Strand the lamps were but misty splotches of diffused light which threw a feeble circular glimmer upon the slimy pavement. The yellow glare from the shop-windows streamed out into the steamy, vaporous air, and threw a murky, shifting radiance across the crowded thoroughfare. There was, to my mind, something eerie and ghost-like in the endless procession of faces which flitted across these narrow bars of light,—sad faces and glad, haggard and merry.

Like all human kind, they flitted from the gloom into the light, and so back into the gloom once more. I am not subject to impressions, but the dull, heavy evening, with the strange business upon which we were engaged, combined to make me nervous and depressed. I could see from Miss Morstan's manner that she was suffering from the same feeling. Holmes alone could rise superior to petty influences. He held his open note-book upon his knee, and from time to time he jotted down figures and memoranda in the light of his pocket-lantern.

At the Lyceum Theatre the crowds were already thick at the side-entrances. In front a continuous stream of hansoms and four-wheelers were rattling up, discharging their cargoes of shirt-fronted men and beshawled, bediamonded women. We had hardly reached the third pillar, which was our rendezvous, before a small, dark, brisk man in the dress of a coachman accosted us.

"Are you the parties who come with Miss Morstan?" he asked.

"I am Miss Morstan, and these two gentlemen are my friends," said she.

He bent a pair of wonderfully penetrating and questioning eyes upon us.

"You will excuse me, miss," he said with a certain dogged manner, "but I was to ask you to give me your word that neither of your companions is a police-officer."

"I give you my word on that," she answered.
He gave a shrill whistle, on which a street Arab led across a four-wheeler and opened the door. The man who had addressed us mounted to the box, while we took our places inside. We had hardly done so before the driver whipped up his horse, and we plunged away at a furious pace through the foggy streets.

The situation was a curious one. We were driving to an unknown place, on an unknown errand. Yet our invitation was either a complete hoax,—which was an inconceivable hypothesis,—or else we had good reason to think that important issues might hang upon our journey. Miss Morstan's demeanor was as resolute and collected as ever. I endeavored to cheer and amuse her by reminiscences of my adventures in Afghanistan; but, to tell the truth, I was myself so excited at our situation and so curious as to our destination that my stories were slightly involved. To this day she declares that I told her one moving anecdote as to how a musket looked into my tent at the dead of night, and how I fired a double-barrelled tiger cub at it. At first I had some idea as to the direction in which we were driving; but soon, what with our pace, the fog, and my own limited knowledge of London, I lost my bearings, and knew nothing, save that we seemed to be going a very long way. Sherlock Holmes was never at fault, however, and he muttered the names as the cab rattled through squares and in and out by tortuous by-streets.

"Rochester Row," said he. "Now Vincent Square. Now we come out on the Vauxhall Bridge Road. We are making for the Surrey side, apparently. Yes, I thought so. Now we are on the bridge. You can catch glimpses of the river."

We did indeed get a fleeting view of a stretch of the Thames with the lamps shining upon the broad, silent water; but our cab dashed on, and was soon involved in a labyrinth of streets upon the other side.
"Wordsworth Road," said my companion. "Priory Road. Lark Hall Lane. Stockwell Place. Robert Street. Cold Harbor Lane. Our quest does not appear to take us to very fashionable regions."
We had, indeed, reached a questionable and forbidding neighborhood. Long lines of dull brick houses were only relieved by the coarse glare and tawdry brilliancy of public houses at the corner.

Then came rows of two-storied villas each with a fronting of miniature garden, and then again interminable lines of new staring brick buildings,—the monster tentacles which the giant city was throwing out into the country. At last the cab drew up at the third house in a new terrace. None of the other houses were inhabited, and that at which we stopped was as dark as its neighbors, save for a single glimmer in the kitchen window. On our knocking, however, the door was instantly thrown open by a Hindoo servant clad in a yellow turban, white loose-fitting clothes, and a yellow sash. There was something strangely incongruous in this Oriental figure framed in the commonplace door-way of a third-rate suburban dwelling-house.

En busca de una solucin

Eran ms de las cinco y media cuando regres Holmes. Vena contento, animado y de excelente humor, un estado de nimo que en l se alternaba con s de la ms negra depresin.
––No hay gran misterio en este asunto ––dijo, tomando la taza de t que yo le haba servido––. Parece que los hechos slo iten una nica explicacin.
––Cmo? Ya lo ha resuelto?
––Bueno, eso es mucho decir. He descubierto un hecho muy sugerente, eso es todo. Eso s, es muy sugerente. Todava falta aadir los detalles. Consultando los archivos del Times, he descubierto que el mayor Sholto, de Upper Norwood, que sirvi en el trigsimo cuarto de Infantera de Bombay, falleci el 28 de abril de 1882.
––Seguro que soy muy obtuso, Holmes, pero no acabo de ver qu sugiere eso.
––No? Me sorprende usted. Pues mrelo de esta manera. El capitn Morstan desaparece. La nica persona de Londres a la que podra haber visitado es el mayor Sholto. El mayor Sholto niega saber que Morstan hubiera estado en Londres. Cuatro aos despus, Sholto muere. Menos de una semana despus de su muerte, la hija del capitn Morstan recibe un valioso regalo, que se repite un ao tras otro, y ahora todo culmina en una carta que la describe como perjudicada. A qu perjuicio puede referirse si no es a la prdida de su padre? Y por qu iban a comenzar los regalos inmediatamente despus de la muerte de Sholto, a menos que el heredero de ese Sholto supiera algo sobre el misterio y deseara ofrecer una compensacin? Tiene usted alguna teora alternativa que se ajuste a los hechos?
––Pues qu compensacin tan extraa! Y qu manera tan extraa de hacerlo! Por qu tendra que escribirle esa carta ahora, y no hace seis aos? Y adems, la carta habla de hacer justicia. Qu justicia se le puede hacer? No ir a suponer que su padre sigue vivo. Y, que nosotros sepamos, no hay ninguna otra injusticia en este caso.
––Hay ciertas dificultades; claro que hay ciertas dificultades ––dijo Sherlock Holmes, pensativo––. Pero la expedicin de esta noche las resolver todas. Ah!, Ah viene un coche, y en l la seorita Morstan. Est usted listo? Pues vayamos bajando, porque ya pasa un poco de la hora.
Recog mi sombrero y mi bastn ms pesado, pero me fij en que Holmes sacaba su revlver del cajn y se lo meta en el bolsillo. Estaba claro que pensaba que nuestro trabajo de aquella noche era cosa seria.
La seorita Morstan vena envuelta en una capa oscura, y su expresivo rostro estaba sereno, pero plido. No habra sido mujer si no hubiera sentido cierta aprensin ante la extraa empresa en la que nos estbamos embarcando, pero su dominio de s misma era perfecto y respondi con soltura a las pocas preguntas nuevas que Sherlock Holmes le plante.
––El mayor Sholto era muy amigo de pap ––dijo––. Sus cartas estaban llenas de comentarios sobre el mayor. El y pap estaban al mando de las tropas de las islas Andaman, de manera que vivieron muchas experiencias juntos. Por cierto, en el escritorio de pap encontramos un extrao papel que nadie consigui entender. No creo que tenga la menor importancia, pero pens que tal vez le gustara verlo y lo he trado. Aqu lo tiene.
Holmes desdobl con cuidado el papel y lo alis sobre su rodilla. A continuacin, lo examin muy meticulosamente con su lupa.
––Es papel de fabricacin india ––coment––. Estuvo alguna vez clavado a un tablero. El esquema dibujado en l parece el plano de parte de un gran edificio, con muchas salas, pasillos y pasadizos. En un punto hay una crucecita trazada con tinta roja, y encima de ella pone 3,37 desde la izquierda, escrito a lpiz y casi borrado. En la esquina inferior izquierda hay un curioso jeroglfico, como cuatro cruces en lnea, con los brazos tocndose. Al lado han escrito, con letra bastante mala y torpe, El signo de los cuatro.– –Jonathan Small, Mahomet Singh, Abdullah Khan, Dost Akbar. No, confieso que no veo ninguna relacin con el asunto. Pero est claro que se trata de un documento importante. Lo han tenido cuidadosamente guardado en una libreta de bolsillo, porque est igual de limpio por un lado que por el
otro.
––Lo encontramos en su libreta de bolsillo.
––Pues gurdelo con cuidado, seorita Morstan, porque puede que nos sea til. Empiezo a sospechar que este caso puede resultar mucho ms complicado y sutil de lo que supuse al principio. Tendr que reconsiderar mis ideas.
Se recost en el asiento del coche y comprend, por su ceo fruncido y su mirada ausente, que estaba pensando intensamente. La seorita Morstan y yo charlamos en voz baja acerca de nuestra expedicin y su posible resultado, pero nuestro compaero mantuvo su impenetrable reserva hasta el final del trayecto.
Estbamos en septiembre y an no eran las siete de la tarde, pero haba hecho un da muy desapacible, y una niebla densa y hmeda se extenda a poca altura sobre la gran ciudad. Por encima de las calles embarradas flotaban tristes nubarrones del mismo color que el barro. A lo largo del Strand, las farolas eran meros borrones de luz difusa, que proyectaban un dbil reflejo circular sobre el resbaladizo pavimento. Las luces amarillas de los escaparates se difuminaban en el aire cargado de vapores, esparciendo un turbio y palpitante resplandor por la concurrida avenida. Me daba la impresin de que haba algo misterioso y fantasmal en la interminable procesin de rostros que atravesaban fugazmente las estrechas franjas de luz: rostros tristes y alegres, angustiados y felices. Como la totalidad del gnero humano, pasaban velozmente de las tinieblas a la luz, slo para volver a sumirse en las tinieblas. No soy fcil de impresionar, pero aquella tarde lgubre y sombra, combinada con el extrao asunto en el que nos habamos embarcado, haba conseguido deprimirme y ponerme nervioso. Por la manera de actuar de la seorita Morstan, me di cuenta de que ella senta algo parecido. Slo Holmes estaba por encima de tan funestas influencias. Sostena su cuaderno de notas abierto sobre las rodillas, y de vez en cuando trazaba nmeros y anotaciones, a la luz de su linterna de bolsillo.
En el Lyceum, la muchedumbre se apretujaba ya ante las entradas laterales. Delante de la puerta principal discurra con estrpito una continua sucesin de coches de dos y cuatro ruedas, que descargaban sus cargamentos de caballeros con pechera almidonada y damas cubiertas de chales y diamantes. Apenas habamos llegado a la tercera columna, lugar de nuestra cita, cuando nos abord un hombre menudo, moreno y gil, vestido de cochero.
––Son ustedes las personas que vienen con la seorita Morstan? –– pregunt.
––Yo soy la seorita Morstan, y estos dos caballeros son amigos mos –– dijo ella.
El hombre nos mir de refiln, con ojos increblemente penetrantes e inquisitivos.
––Tendr que perdonarme, seorita ––dijo con cierto tono obstinado––, pero tengo que pedirle que me d su palabra de que ninguno de sus acompaantes es agente de polica.
––Le doy mi palabra ––respondi ella.
El hombre emiti un agudo silbido y, en respuesta al mismo, un golfillo acerc un coche de cuatro ruedas y abri la puerta. Nuestro interlocutor subi al pescante, mientras nosotros nos acomodbamos dentro. Apenas nos habamos sentado, cuando el cochero fustig al caballo y partimos a toda velocidad por las calles cubiertas de espesa niebla.
Era una situacin curiosa. Nos dirigamos a un lugar desconocido con una misin desconocida. O bien la invitacin era una completa burla ––hiptesis que resultaba inconcebible––, o bien tenamos buenas razones para pensar que de aquel trayecto podan depender cuestiones muy importantes. La actitud de la seorita Morstan era tan decidida y serena como siempre. Me propuse animarla y entretenerla con ancdotas de mis aventuras en Afganistn; pero, a decir verdad, yo mismo estaba tan excitado por la situacin y senta tanta curiosidad por conocer nuestro destino, que mis relatos se embarullaron un poco. En el da de hoy, ella todava sigue insistiendo en que le cont una emocionante historia en la que una escopeta se asom a mi tienda en mitad de la noche, y yo le dispar con un cachorro de tigre de dos caones.
Al principio, tena cierta idea de la direccin en la que bamos, pero con la velocidad que llevbamos, la niebla y mi limitado conocimiento de Londres, no tard en desorientarme y ya no supe nada ms, excepto que pareca que bamos muy lejos. En cambio, Sherlock Holmes no se despist ni una vez, e iba musitando los nombres a medida que el coche atravesaba plazas y se internaba por tortuosas callejuelas.
––Rochester Road ––deca––. Y ahora, Vincent Square. Ahora saldremos a la calle del puente de Vauxhall. Parece que vamos hacia la parte de Surrey. S, lo que yo deca. Ya estamos en el puente. Se alcanza a ver el ro.
En efecto, pudimos ver de manera fugaz un tramo del Tmesis, con las farolas brillando sobre sus anchas y tranquilas aguas; pero el coche sigui adelante a toda velocidad y se introdujo rpidamente en el laberinto de calles de la otra orilla.
––Wandsworth Road ––dijo mi compaero––. Priory Road. Larkhall Lane. Stockwell Place. Robert Street. Coldharbour Lane. No parece que nuestra expedicin nos lleve a zonas muy elegantes.
Efectivamente, habamos llegado a una barriada bastante sospechosa y desagradable. Largas y montonas hileras de casas de ladrillo, alegradas tan slo por el turbio resplandor y los vulgares adornos de los bares de las esquinas. Pasamos luego ante varias manzanas de casas de dos plantas, todas ellas con un minsculo jardn delante; y otra vez las interminables filas de edificios nuevos de ladrillo, monstruosos tentculos que la gigantesca ciudad extenda hacia el campo. Por fin, el coche se detuvo ante la tercera casa de una manzana recin construida. Ninguna de las otras casas estaba habitada, y la que pareca nuestro destino estaba tan a oscuras como sus vecinas, excepto por un dbil resplandor en la ventana de la cocina. Sin embargo, en cuanto llamamos a la puerta, la abri al instante un sirviente indio ataviado con turbante amarillo, ropa blanca holgada y una faja amarilla. Haba algo extrao e incongruente en aquella figura oriental enmarcada en el umbral de una vivienda suburbana de tercera clase.
––El sahib los aguarda ––dijo.
An no haba terminado de hablar cuando una voz aguda y chillona grit desde alguna habitacin interior: ––Hazlos pasar, khitmutgar. Que pasen en seguida.