The Trisolarians from the Three-Body Problem novels are planning to invade Earth... only it's the Earth of the Star Trek-verse.
They've already launched numerous Sophons on the planet, which had been monitoring and communicating information to the Trisolarian fleet for decades.
Starfleet has only 5 years of prep-time before all Trisolarians arrive. They can plead for aid from their allies in the United Federation of Planets.
Can they successfully fend off the incoming invasion by the Trisolarians?