I think he's gone out of his mind.

He'll die if he's left.
It's a matter of life or death, I tell you.

He's too strong for me to manage alone.

Someone must come too." The brisk man looked at the engineer, and the French engineer looked at him.
"What's he doing out there ?" "He's just out by the wood." It ended in the two men finding snow-shoes and going with Trenholme across the snow.
They all three peered through the dimness at the space between them and the wood, and they saw nothing.

They retraced the snow-shoe tracks and came to the place where the irregular circuit had been made near the end of the wood.