"THE JANUS GATE"
book one of three
The crew of the "U.S.S. Enterprise(TM) " is exploring the seemingly peaceful and uninhabited world of M-3107 when a bizarre and inexplicable transporter accident causes both Captain Kirk and Dr. McCoy to vanish completely. Transporter records suggest that the two men were transported "somewhere," but their ultimate destination remains a mystery.
Now in command of the "Enterprise," Spock dispatches a search-and -rescue team -- consisting of Security Chief Giotto, Transporter Technician John Kyle, and Chief Helmsman Hikaru Sulu -- on an urgent mission to recover the missing officers.
But then the rescue team disappears as well!