Key Out of Time

Ashe Gordon and Ross Murdock, angry about the loss of their fellow agent Travis Fox on the planet Topaz, have travelled to the planet Hawaikan, a warm ocean planet, where they intend to set up a time gate. The world is so different from what they expected that they decide on a risky experiment: travel into the past of the planet, accompanied by two mutant dolphins and a female agent of Polynesian ancenstry.