When a key member of The Bureau Underground - a top secret government agency - goes missing, Leroy, a cynical former detective, and Max, a genius "true believer" in the paranormal, are recruited to find him. The two polar opposites must work together to find the agent, while uncovering possible alien activity and chilling "unexplained" paranormal events in their own city of Los Angeles.
Leroy and Max take Jermaine trick-or-treating, although Jermaine hopes they'll drop him off at a party instead. The party becomes the least of their worries when Jermaine is infected with a zombie-esque virus by a demon cat. Meanwhile, Halloween is a busy night, full of paranormal activity, for LaFrey, Annie and Barry at the Bureau Underground.
With the encouragement of Max, Leroy romantically pursues a female cop, while they work on-site at a local resort. As the pair search for the culprit behind a string of murders, Captain Lafrey has Annie and Barry investigate her daughter, who may be sneaking out behind her back with a boy.
LaFrey's boss, Director Romslo, puts the entire office on lockdown when a deadly amphibious creature escapes in The Bureau Underground, giving Max and Leroy only 30 minutes to eliminate the threat.
When Max and Leroy investigate a bizarre incident at an elite country club, they both get a little too invested in their covers and find themselves at odds. Also, Annie accompanies them on the mission, as she frequented many country clubs in her youth.
While Captain Lafrey is out, Annie installs a smooth-talking Artificial Intelligence, "Sam," to manage the office, but Max and Leroy are put to the test when "Sam" turns out to be an evil and powerful force trying to take down the Bureau Underground. All the while, Max is jealous when Leroy makes a new friend.
When a pair of smug actors, Chaz and Jared, from the ghost-hunting show "Ghost Studz," accidentally stumble upon real paranormal activity, Max and Leroy must go undercover on set at an abandoned mental hospital to save them. Leroy resents the "perks" the actors get with their fame, realizing he and Max will never enjoy the same benefits working in a top-secret bureau. Meanwhile, Barry demands some perks of his own.
When a young girl goes missing at a haunted hayride, Max and Leroy go undercover to determine if it was a paranormal act or just a publicity stunt. Meanwhile, Barry brainstorms ways to "bro-bond" with Max and Leroy.
Max and Leroy invite Annie to tag along on their next case, as she is an expert on the killer creature they are trying to find, but Max's survival skills are put to the test when they lose their way in the woods. Back at The Bureau Underground, Barry proves himself an asset in solving Captain LaFrey's dating struggles.
When new cases become few and far between at the Bureau, Max obsesses over his multiverse theory and Leroy grows restless - until they discover a suspicious wire in the office that they think might be a secret surveillance system.
Everyone, including Captain LaFrey, is surprised and alarmed when The Bureau Underground is assigned a new captain, Merv Minette. Minette doesn't seem thrilled with his new post either, and halts Max and Leroy's investigation of the suspicious wire.
Leroy brings in a psychic to help The Bureau figure out who bugged their office. Although he and the rest of the team are determined to make something of the findings – in order to reclaim the office from Merv – Max refuses to give in to the superstitions.
When an article is published revealing The Bureau Underground to the public, Merv asks Leroy to interrogate his coworkers to find out who may have leaked the information.
Leroy shocks Max with a personal confession about Annie just as they see what appears to be an alien ship in the sky. Back in the office bullpen, everyone views Max’s UFO footage but also accidentally overhears Leroy’s confession on the video. To Merv’s dismay, everyone is more intrigued by what they heard than by the UFO.
The BU is called upon to investigate a mysterious airplane voyage. They are immediately mocked and shut out by the FBI and FAA, but are determined to solve the case and prove themselves. Max and Annie make a startling discovery, but when Merv gets wind of their theory of what happened to the plane, he refuses to allow them to present their findings to the head of the task force for fear of being made laughingstocks.
While trying to prove their worth to Captain LaFrey and the rest of The Bureau Underground, Leroy and Max finally have a lead on the whereabouts of Agent Checker. Leroy finds himself in the odd position of being the believer when Max loses faith that they have what it takes.