The first season of “Zoo” began with seemingly unrelated animal attacks around the world. A lion killed someone on an African safari. A bear terrorized a woman in her home in France. Then all the cats in an American neighborhood collectively decided to climb a single tree and plot revenge. The cats and later all the animals, were working together to take over because they were infected with a man-made virus. The main characters, Jackson, Abraham, Jamie and Mitch, teamed up to stop the chaos. The show was a thriller, a mystery and even a little romance. And it was fun. Now in its third season, the series has little of those original characteristics.

Season three begins 10 years from season two when the team found a cure for the animal virus but could not stop a shady organization from releasing a sterilization agent into the air, which marked the beginning of the end for humanity. Faced with a new world, the team has gone their separate ways. Jamie (Kristen Connolly) is working to bring down the organization that started the end of the world. Mitch (Billy Burke) is trying to recover from being imprisoned in Siberia. Jackson (James Wolk) is fighting viscous hybrid animals along the U.S. West Coast and Abraham (Nonso Anozie), now married to Dariela (Alyssa Diaz), is raising his son (part of the last generation) while researching ways to reverse sterilization.

The best part about “Zoo” is that it doesn’t take itself too seriously but this season things have veered into ridiculous. In one scene, Mitch cracks a few sarcastic one-liners as Jamie drills a hole in his head attempting to remove an implant. Then he guides her through his own brain surgery while he’s sitting in a chair. It all takes place on a plane in mid-flight. And Jamie’s skills don’t stop at impromptu neurosurgery at 35,000 feet. In the first episode, she has surprisingly good aim when shooting a gun, (like expert sniper aim) and she doesn’t hesitate to painfully extract information from a bad guy she keeps locked in a cell.

When a show jumps years ahead in its storytelling, it’s a chance to refresh the plot and characters but “Zoo’s” 10-year leap doesn’t offer anything that new. The team is still fighting weird animal behavior and evil corporate interests while the changes in the characters’ situations have left them with little of their past chemistry. Jackson and Abe have lost their brotherly bond and Dariela’s hardcore military edge has taken a back seat. Jamie’s crusade has turned her from a plucky reporter to a bitter avenger and Mitch’s dry wit, usually a funny commentary on the characters’ predicaments falls flat now that those predicaments are so eye-rolling.

Past seasons of “Zoo” had far-fetched elements but watching a rag tag group of friends try to stop man’s best friend from plotting a takeover was just silly enough to be entertaining. This season, it’s just silly.

“Zoo” is on Thursdays at 10 p.m. EDT on CBS.

— Melissa Crawley is the author of “Mr. Sorkin Goes to Washington: Shaping the President on Television’s ‘The West Wing’” and the recently released “The American Television Critic.” She has a Ph.D. in media studies and is a member of the Television Critics Association. To comment on Stay Tuned, email her at staytuned@outlook.com or follow her on Twitter at @MelissaCrawley.