For four seasons Eureka has been science fiction’s favorite little town, and its quirky community of geniuses has become a staple of Syfy’s primetime lineup. “Eureka” is currently Syfy’s longest-running scripted series and returns for its fifth and final season on Monday, April 16, at 7 p.m. As the show starts up its final season, however, viewers will need to be either die-hard fans of the show or Eureka-like geniuses themselves to understand and follow exactly what is going on.

“Eureka” is based in a small town in the Pacific Northwest where the government has assembled a conglomeration of geniuses to conduct top-secret research. This assembly has resulted in the creation of a place where literally anything can happen. The main character is Sheriff Jack Carter (Colin Ferguson), the one average Joe in a town of smart people, and it’s his job to make sure that the eccentric residents of Eureka don’t blow themselves, or the town itself, to bits.

Season four left the citizens of Eureka reeling after the government’s latest project for them, which included assembling a crew and spaceship, the Astraeus, for a faster-than-light journey to one of the moons of Saturn, ended in a mislaunch resulting in the mysterious disappearance of both the Astraeus and her crew. The incident left many of the show’s main characters separated from family members or loved ones, and with a mystery: where is the Astraeus and her crew, and what caused the ship to launch unstoppably early?

In the season five premiere this Monday, the crew of the Astraeus returns, but while only a few hours have passed for them, during which they unwittingly have to emergency land the ship back in Eureka, more than four years have passed for the rest of the town. The crew and the town then have to cope with the various changes that have taken place, both in the administration of the town and in each of their personal lives.

Over the course of the season’s first few episodes, the citizens of Eureka, led by Sheriff Carter, will work to discover what really happened to the Astraeus, who is responsible, and who they can trust. It is during this time that viewers must watch the events of the show carefully so that they can keep track of what happens in the show’s reality and what is only virtual. And viewers beware; one or more of Eureka’s finest will not survive the startup of this season.

“Eureka” has struggled lately to find a balance between comedy and character drama, having overloaded many of its characters with personal problems or conflicts and drifted away from its wacky, fun-with-science roots. But if the beginning of season five is any indication, then it looks like “Eureka” will be going out on a high note.

While the show continues to be mostly family-friendly, it does contain some sexual references and intense moments that might not be suitable for children. If the show can maintain the standard set by the early episodes of the coming season, then its creators can say that they’ve discovered something worthwhile. Otherwise, if it falls back into its pattern of overloaded personal drama and soap opera style relationships, then there will be no “eureka” for “Eureka.”