Jarvis, smiling at Sally and taking note of her pink cheeks, detained her with an injunction.  “Whatever you find,” he stipulated, “make no outcry.  Retain your composure.  Remember your friends are close at hand.  Three raps on the inside of this door will summon four stout retainers to your side.  Are you ready?”

“Ready.”

“Remember that defunct beetles are harmless, old clothes retain no characteristics of their former owners, no matter how blood-thirsty, and empty bottles probably never contained fatal potions.  If the place is dark, press your finger on this”—­he thrust a small electric search-light into her hand—­“and the mystery will be illumined.  Brave lady, enter!”

He opened the door just wide enough to admit the slim figure in black, which slipped through and promptly closed the door upon itself.

Josephine interfered.

“Jarvis, don’t let her shut that door!  Something might happen!  There might be a—­hole in the floor.”

“She has blue eyes and you black!” retorted Jarvis.  “She has golden locks, you raven.  Don’t let the outward attributes belie themselves like that.”

“Sh!—­Sh-h!” Josephine held up a beseeching finger.

Everybody listened.  A silence ensued, unbroken by raps or sounds of any sort.  When this had continued for some five minutes, Josephine spoke urgently:  “Jarvis Burnside, open that door!  It’s all right to joke, but things do happen, and it’s not right to fool this way!”

“What’s the matter with you, Jo Burnside?” demanded Max, while Jarvis, looking quizzical, still held the door.  “Don’t you know Sally well enough to know she’s not afraid of her shadow?  She’s playing the game through.  She’ll come back in her own good time, when she’s thoroughly explored whatever’s behind that door.  A mouse won’t give her hysterics, or a flapping window-shade make her scream.”

Josephine held her peace, but she looked at Bob.  Bob was genuinely uneasy, though determined not to show it.  There is undeniably a peculiar atmosphere about old and unused houses, and queer fancies are prone to take possession of those who explore them.  It was ten years since this house had been lived in.  There was something odd about its having been so completely deserted, with not even a tenant left to occupy its kitchen regions and look after it.  And the lock on this door had been strangely resistant.

Josephine suddenly opened her lips to say:  “I shall not stand here waiting another minute!” when three raps on the door brought back her composure.

Jarvis, himself looking a trifle relieved, promptly turned the knob.  But he could not open the door.

“It must be a spring-lock,” he grunted disgustedly.  “Idiot that I was!  All right, Sally!” he called.  “Got to work the tools over again.”

“Sally, O Sally, are you all right?” called Josephine.

There was no reply.  Jarvis worked rapidly, repeating his former processes with an impatient hand.  When the lock yielded once more, he threw the door open, and the others crowded up the steps.