The sentry on duty knocked, opened the door, and admitted a weather-stained aide-de-camp, warning her respectfully:

"Orders for you, ma'am."

The Special Messenger cleared her eyes, breathing unevenly, and unsealed the dispatch which the officer handed her.

When she read it she opened a door and called sharply to a hospital orderly, who came running:

"Fit me with a rebel cavalry uniform--you've got that pile of disinfected clothing in the basement. I also want one of our own cavalry uniforms to wear over it--anything that has been cleaned. Quick, Williams; I've only a few minutes to saddle! And bring me that bundle of commissions taken from the rebel horsemen that were brought in yesterday."

And to the mud-splashed aide-de-camp who stood waiting, looking out of the window at the gunboat which was now churning in toward the wharf, billows of inky smoke pouring from the discolored stacks:

"Please tell the general that I go aboard in half an hour. Tell him I'll do my best." In a lower voice: "Ask him not to forget my brother--if matters go wrong with me. He has given me his word.... And I think that is all, thank you."

The A.-D.-C. said, standing straight, hollow-backed, spurred heels together:

"Orders are verbally modified, madam."

"What?"

"If you do not care to go--it is not an order--merely a matter of volunteering.... The general makes no question of your courage if you choose to decline."

She said, looking at the officer a little wearily:

"Thank the general. It will give me much pleasure to fulfill his request. Ask him to bear my brother in mind; that is all."

The A.-D.-C. bowed to her, cap in hand, then went out, making considerable racket with sabre and boots.

Half an hour later a long, deep, warning blast from the gunboat's whistle set the echoes flying through the hills.

Aboard, leading her horse, the Special Messenger, booted and spurred, in a hybrid uniform of a subaltern of regulars, handed the bridle to a sailor and turned to salute the quarterdeck.

The United States gunboat, _Kiowa_, dropped anchor at the railroad wharf two days later, and ran out a blackened gangplank. Over it the Special Messenger, wrapped in her rubber cloak, led her horse to shore, mounted, and galloped toward the hill where the flag of corps headquarters was flapping in the wet wind.

The rain ended as she rode inland; ahead of her a double rainbow glowed and slowly faded to a rosy nimbus.

Corps headquarters was heavily impressive and paternally polite, referring her to headquarters of the unattached cavalry division.

She remounted, setting her horse at an easy canter for the intervening two miles, riding through acres of tents and vistas of loaded wagon trains; and at last an exceedingly ornamental staff officer directed her to her destination, and a few moments later she dismounted and handed her bridle to an orderly, whose curiously fashioned forage cap seemed strangely familiar.

As the Special Messenger entered his tent and saluted, the colonel of the Fourth Missouri Cavalry rose from a camp chair, standing over six feet in his boots. He was magnificently built; his closely clipped hair was dark and curly, his skin smoothly bronzed and flushed at the cheek bones; his allure that of a very splendid and grave and youthful god, save for the gayly impudent uptwist of his short mustache and the stilled humor in his steady eyes.

His uniform was entirely different from the regulation--he wore a blue forage cap with short, heavy visor of unpolished leather shadowing the bridge of his nose; his dark blue jacket was shell-cut; over it he wore a slashed dolman trimmed at throat, wrists and edges with fur; his breeches were buff; his boots finished at the top with a yellow cord forming a heart-shaped knot in front; at his heels trailed the most dainty and rakish of sabres, light, graceful, curved almost like a scimiter.

All this is what the Special Messenger saw as she entered, instantly recognizing a regimental uniform which she had never seen but once before in her brief life. And straight through her heart struck a pain swift as a dagger thrust, and her hand in its buckskin gauntlet fell limply from the peak of her visor, and the color died in her cheeks.

What the colonel of the Fourth Missouri saw before him was a lad, slim, rather pale, dark-eyed, swathed to the chin in the folds of a wet poncho; and he said, examining her musingly and stroking the ends of his curt mustache upward:

"I understood from General Sheridan that the Special Messenger was to report to me. Where is she?"

The lightning pain of the shock when she recognized the uniform interfered with breath and speech; confused, she raised her gloved hand and laid it unconsciously over her heart; and the colonel of the Fourth Missouri waited.

"I am the Special Messenger," she said faintly.

For a moment he scarcely understood that this slender young fellow, with dark hair as closely clipped and as curly as his own, could be a woman.

Stern surprise hardened his narrowing gaze; he stood silent, handsome head high, looking down at her; then slowly the latent humor flickered along the edges of lip and lid, curbed instantly as he bowed, faultless, handsome--only the persistently upturned mustache impairing the perfectly detached and impersonal decorum with a warning of the _beau sabreur_ behind it all.

"Will you be seated, madam?"

"Thank you."

She sat down; the wet poncho was hot and she shifted it, throwing one end across her shoulder. In her uniform she appeared willowy and slim, built like a boy, and with nothing of that graceful awkwardness which almost inevitably betrays such masqueraders. For her limbs were straight at the knees and faultlessly coupled, and there seemed to be the adolescent's smooth lack of development in the scarcely accented hips--only a straightly flowing harmony of proportion--a lad's grace muscularly undeveloped.

Two leather straps crossed her breast, one weighted with field glasses, the other with a pouch. From the latter she drew her credentials and would have risen to present them, but the colonel of the Fourth Missouri detained her with a gesture, himself rose, and took the papers from her hand.

While he sat reading, she, hands clasped in her lap, gazed at his well-remembered uniform, busy with her memories once more, and the sweetness of them--and the pain.

They were three years old, these memories, now glimmering alive again amid the whitening ashes of the past; only three years--and centuries seemed to dim the landmarks and bar the backward path that she was following to her girlhood!

She thought of the white-pillared house as it stood at the beginning of the war; the severing of old ties, the averted faces of old friends and neighbors; the mortal apprehension, endless suspense; the insurgent flags fluttering from porch and portico along the still, tree-shaded street; her own heart-breaking isolation in the community when Sumter fell--she an orphan, alone there with her brother and bedridden grandfather.

And she remembered the agony that followed the news from Bull Run, the stupor that fell upon her; the awful heat of that battle summer; her evening prayers, kneeling there beside her brother; the red moons that rose, enormous, menacing, behind the trees; and the widow bird calling, calling to the dead that never answer more.

Her dead? Why _hers_? A chance regiment passing--cavalry wearing the uniform and number of the Fourth Missouri. Ah! she could see them again, sun-scorched, dusty, fours crowding on fours, trampling past. She could see a young girl in white, fastening the long-hidden flag to its halyards as the evening light faded on the treetops!... And then--and then--_he_ came--into her life, into her house, into her heart, alas!--tall, lean, calm-eyed, yellow-haired, wrapped in the folds of his long, blue mantle!... And she saw him again--a few moments before his regiment charged into that growling thunder beyond the hills somewhere.

And a third time, and the last, she saw him, deathly still, lying on her own bed, and a medical officer pulling the sheet up over his bony face.

The colonel of the Fourth Missouri was looking curiously at her; she started, cleared the dimness from her eyes, and steadied the trembling underlip.

After a moment's silence the colonel said: "You undertake this duty willingly?"

She nodded, quietly touching her eyes with her handkerchief.

"There is scarcely a chance for you," he observed with affected carelessness.

She lifted her shoulders in weary disdain of that persistent shadow called danger, which had long since become too familiar to count very heavily.

"I am not afraid--if that is what you mean. Do you think you can get me through?"

The colonel said coolly: "I expect to do my part. Have you a rebel uniform?"

She nodded.

"Where is it?"

"On me--under this."