The Intruder had returned for a second attack.

Dr. Silence moved slowly backwards and took up his position on the
hearthrug, keying himself up to a condition of concentrated attention.

He noted that Flame stood beside him, facing the room, with body
motionless, and head moving swiftly from side to side with a curious
swaying movement. His eyes were wide open, his back rigid, his neck and
jaws thrust forward, his legs tense and ready to leap. Savage, ready for
attack or defence, yet dreadfully puzzled and perhaps already a little
cowed, he stood and stared, the hair on his spine and sides positively
bristling outwards as though a wind played through it. In the dim
firelight he looked like a great yellow-haired wolf, silent, eyes
shooting dark fire, exceedingly formidable. It was Flame, the terrible.

Smoke, meanwhile, advanced from the door towards the middle of the room,
adopting the very slow pace of an invisible companion. A few feet away
it stopped and began to smile and blink its eyes. There was something
deliberately coaxing in its attitude as it stood there undecided on the
carpet, clearly wishing to effect some sort of introduction between the
Intruder and its canine friend and ally. It assumed its most winning
manners, purring, smiling, looking persuasively from one to the other,
and making quick tentative steps first in one direction and then in the
other. There had always existed such perfect understanding between them
in everything. Surely Flame would appreciate Smoke's intention now, and
acquiesce.

But the old collie made no advances. He bared his teeth, lifting his
lips till the gums showed, and stood stockstill with fixed eyes and