The Man In The Brown Suit

The Man in the Brown Suit is described by Wikipedia as "a work of detective fiction by British writer Agatha Christie, first published in the UK by The Bodley Head on 22 August 1924 and in the US by Dodd, Mead and Company later in the same year. The character Colonel Race is introduced in this novel.

Anne Beddingfeld is on her own and ready for adventures when one comes her way. She sees a man die in a tube station and picks up a piece of paper dropped nearby. The message on the paper leads her to South Africa as she fits more pieces of the puzzle together about the death she witnessed, a murder in England the next day, and attempts to kill her on the ship en route to Cape Town."

Excerpt:

PROLOGUE
Nadina, the Russian dancer who had taken Paris by storm, swayed to the sound of the applause, bowed and bowed again. Her narrow black eyes narrowed themselves still more, the long line of her scarlet mouth curved faintly upwards. Enthusiastic Frenchmen continued to beat the ground appreciatively as the curtain fell with a swish, hiding the reds and blues and magentas of the bizarre décors. In a swirl of blue and orange draperies the dancer left the stage. A bearded gentleman received her enthusiastically in his arms. It was the Manager.
“Magnificent, petite, magnificent,” he cried. “To-night you have surpassed yourself.” He kissed her gallantly on both cheeks in a somewhat matter-of-fact manner.
Madame Nadina accepted the tribute with the ease of long habit and passed on to her dressing-room, where bouquets were heaped carelessly everywhere, marvellous garments of futuristic design hung on pegs, and the air was hot and sweet with the scent of the massed blossoms and with more sophisticated perfumes and essences. Jeanne, the dresser, ministered to her mistress, talking incessantly and pouring out a stream of fulsome compliment.
A knock at the door interrupted the flow. Jeanne went to answer it, and returned with a card in her hand.
“Madame will receive?”
“Let me see.”
The dancer stretched out a languid hand, but at the sight of the name on the card, “Count Sergius Paulovitch,” a sudden flicker of interest came into her eyes.
“I will see him. The maize peignoir, Jeanne, and quickly. And when the Count comes you may go.”
“Bien, Madame.”
Jeanne brought the peignoir, an exquisite wisp of corn-coloured chiffon and ermine. Nadina slipped into it, and sat smiling to herself, whilst one long white hand beat a slow tattoo on the glass of the dressing-table.
The Count was prompt to avail himself of the privilege accorded to him—a man of medium height, very slim, very elegant, very pale, extraordinarily weary. In feature, little to take hold of, a man difficult to recognize again if one left his mannerisms out of account. He bowed over the dancer’s hand with exaggerated courtliness.
“Madame, this is a pleasure indeed.”
So much Jeanne heard before she went out closing the door behind her. Alone with her visitor, a subtle change came over Nadina’s smile.
“Compatriots though we are, we will not speak Russian, I think,” she observed.
“Since we neither of us know a word of the language, it might be as well,” agreed her guest.
By common consent, they dropped into English, and nobody, now that the Count’s mannerisms had dropped from him, could doubt that it was his native language. He had, indeed, started life as a quick-change music-hall artiste in London.
“You had a great success to-night,” he remarked. “I congratulate you.”