For a moment she wondered whether the faint and the heart attack had been a gigantic sham, but remembering the deadly pallor she could hardly credit the supposition.  As she looked the expression disappeared as by magic, and Mrs. Vandemeyer lay inert and motionless as before.  For a moment the girl fancied she must have dreamt it.  But she determined nevertheless to be on the alert.

“Well,” said Julius, “I guess we’d better make a move out of here any way.”

The others fell in with his suggestion.  Sir James again felt Mrs. Vandemeyer’s pulse.

“Perfectly satisfactory,” he said in a low voice to Tuppence.  “She’ll be absolutely all right after a night’s rest.”

The girl hesitated a moment by the bed.  The intensity of the expression she had surprised had impressed her powerfully.  Mrs. Vandemeyer lifted her lids.  She seemed to be struggling to speak.  Tuppence bent over her.

“Don’t—­leave——­” she seemed unable to proceed, murmuring something that sounded like “sleepy.”  Then she tried again.

Tuppence bent lower still.  It was only a breath.

“Mr.—­Brown——­” The voice stopped.

But the half-closed eyes seemed still to send an agonized message.

Moved by a sudden impulse, the girl said quickly: 

“I shan’t leave the flat.  I shall sit up all night.”

A flash of relief showed before the lids descended once more.  Apparently Mrs. Vandemeyer slept.  But her words had awakened a new uneasiness in Tuppence.  What had she meant by that low murmur:  “Mr. Brown?” Tuppence caught herself nervously looking over her shoulder.  The big wardrobe loomed up in a sinister fashion before her eyes.  Plenty of room for a man to hide in that....  Half-ashamed of herself, Tuppence pulled it open and looked inside.  No one—­of course!  She stooped down and looked under the bed.  There was no other possible hiding-place.

Tuppence gave her familiar shake of the shoulders.  It was absurd, this giving way to nerves!  Slowly she went out of the room.  Julius and Sir James were talking in a low voice.  Sir James turned to her.

“Lock the door on the outside, please, Miss Tuppence, and take out the key.  There must be no chance of anyone entering that room.”

The gravity of his manner impressed them, and Tuppence felt less ashamed of her attack of “nerves.”

“Say,” remarked Julius suddenly, “there’s Tuppence’s bright boy.  I guess I’d better go down and ease his young mind.  That’s some lad, Tuppence.”

“How did you get in, by the way?” asked Tuppence suddenly.  “I forgot to ask.”

“Well, Albert got me on the phone all right.  I ran round for Sir James here, and we came right on.  The boy was on the look out for us, and was just a mite worried about what might have happened to you.  He’d been listening outside the door of the flat, but couldn’t hear anything.  Anyhow he suggested sending us up in the coal lift instead of ringing the bell.  And sure enough we landed in the scullery and came right along to find you.  Albert’s still below, and must be just hopping mad by this time.”  With which Julius departed abruptly.