Decent juvenile science fiction from British writer, Hugh Walters, concerning a novel area of manned exploration, the subterranean earth. The book, part of a series about a team of astronauts, dates from the early 1960s, and was inspired, not only by the space program, but the Mohole Project. Here, one team member, Serge, is sent down in a small capsule, just big enough for one, very thin, person. Of course, he gets stuck, and the rest of the team must rescue him. The team has to use their ingenuity, much like the real life NASA astronauts and crew, when various glitches occurred. I only gave it 3 stars because the characters were pretty flat. I had a tough time telling them apart—kind of like the the old Thunderbirds TV show and the team for International Rescue.