With ropes, crampons, chocolate bars and guns, an expedition is sent to the Chile-Argentine border where a volcano, the Viedma, is believed to be active. It may also be the lair of an extinct species of pre-man, the Paranthropus, once sighted by the great-uncle of Miles, a zoologist, also a member of the group. Down they go and up they go, joined by a young Chilean woman who is as fearless as they are; they're attacked by a troupe of Paranthropuses all with rust-red hair and atavistic as anything; the volcano goes off; but they manage to make it back to England with their not-so-living evidence (a head in a crate). . . . A forthright story hour or two on the spoor of the Abominable Snowman with moments (the craggy climb, the fire and ice) of Hammond Innes simplified.