Watch Star Trek IV: The Voyage Home (1986) HD Full Movie Free on SolarMovie. Watch Star Trek IV: The Voyage Home (1986) online free. To save Earth from an alien probe, Admiral James T. Kirk and his fugitive crew go back in time to Sa...To save Earth from an alien probe, Admiral James T. Kirk and his fugitive crew go back in time to San Francisco in 1986 to retrieve the only beings who can communicate with it: humpback whales.