When Bowman warns Floyd to leave Jupiter's orbit within the next two days, Floyd breaks the communication ban between the Discovery and the Leonov. Aware that the two ships don't have enough fuel to make it back to Earth separately if they leave so many weeks ahead of their launch window, they concoct a plan to attach the Leonov to the Discovery, use the Discovery as a booster rocket, then detach the Discovery and use the Leonov for the return trip. They begin to make the preparations, including reprogramming HAL to accept the new orders, although Dr Chandra isn't sure whether HAL will accept them. Two days later, as they count down to launch, the crew notices that the black spot on Jupiter has suddenly begun to shrink, filling up instead with millions of monoliths. HAL notices, too, and requests that the countdown be stopped so that the phenomenon can be studied, forcing Chandra to be truthful about the Discovery's (and HAL's) imminent destruction. Fortunately, HAL understands and proceeds with the countdown. Just before the Discovery is destroyed, Bowman contacts HAL and orders him to point his transmitter towards the Earth and send the following message: ALL THESE WORLDS ARE YOURS EXCEPT EUROPA. ATTEMPT NO LANDING THERE. USE THEM TOGETHER. USE THEM IN PEACE. HAL does as directed and transmits the message until the Discovery blows up. The crew then watches incredulously as Jupiter collapses then explodes, forming a small star. In the final scenes, Floyd composes a letter to his son explaining how the people on Earth will forevermore see two suns in the sky and know that we are not alone. He then goes into cryosleep knowing that the Soviets and the U.S. have, thanks to the message, ceased their hostilities. Meanwhile, centuries later on Europa, the new mini sun has warmed the surface enough to allow vegetation to grow there. A monolith stands in the middle of a lake, waiting for intelligent lifeforms to evolve.