I'm looking for a book that features a group of people that are using a sort of teleportation device to abduct people to the Moon for some purpose (labor? smarts?). Eventually they overpower the people responsible. They can't get back to Earth so the protagonist somehow uses the device to return to Earth to get help. The device was embedded in a rockface and was composed of many metal tubes. He reached in and somehow felt his way to the other side, which was on Earth in a field.
I think the cover had a tiger or something on it against a rocky background. It didn't really have much to do with the plot. It was a slim book. I read it around the 1990s, when I traded my copy of Sleeping Planet for it.