The Quonset by Gales, Tom R., ISBN 1546520872, ISBN-13 9781546520870, Like New Used, Free shipping in the US
A group of friends try to discover why and where their good friend disappeared. They cannot convince the police they have enough evidence to file a missing persons report. They have no idea whether he is in danger or worse. They decide they can't abandon him, no matter the danger that might be involved.