Extract the answer to the following question from the movie plot. If the question isn't answerable, please output "Can't answer". Question: What device does Khan detonate? Title: Star Trek III: The Search for Spock Movie plot: The USS Enterprise, having survived it's battle with Khan Noonien Singh, is returning to Earth. With a few hours left in their journey, Kirk remarks in his log that there is a heavy feeling amongst the crew on the ship, having lost their science officer, Captain Spock, whom sacrificed himself to insure the Enterprise would not be destroyed by Khan. Kirk has Uhura check for a hailing signal from Starfleet but finds there isn't one. When asked by a cadet if they will receive a hero's welcome at home, Kirk thinks they will since they've "paid with their dearest blood."In a remote area of space, a Klingon female, Valkris, waits on a small freighter for a signal from her commanding officer. Commander Kruge responds and Valkris transmits stolen data to him on the Genesis project. When asked by Kruge if she had seen the information, she replies she had.Kruge tells her that it's unfortunate that she had. With the captain of the freighter asking when he'll be paid, Kruge's ship, a Klingon Bird-of-Prey, deactivates it's cloaking device and swings into attack, blasting apart the freighter and flying off.At Earth the Enterprise arrives at the orbiting Spacedock. While the ship docks the crew catches sight of the fleet's newest and most advanced ship, Excelsior. Sulu remarks that Excelsior has a new technology called "transwarp" drive. A skeptical Mr. Scott is scornful however Kirk scolds him gently, saying "young minds, fresh ideas." A warning alarm suddenly sounds; someone has broken into Mr. Spock's quarters which Kirk had ordered sealed. Kirk goes there himself and finds Dr. McCoy, whom appears to be suffering from mental trauma. He tells Kirk that "he left him back on Genesis" and that he has to "climb the steps of Mount Selaya" on the planet Vulcan. McCoy collapses, unconscious, and Kirk calls for the medics.Back on Kruge's ship, he and his first officer study the Genesis materials and determine that it can be an invincible weapon. He orders a course set for the Genesis Planet.On Earth, the crew of the Enterprise is...
A:
Genesis