It’s the 1960s. The height of the Cold War. The rural town of Granite Flats, Colorado, suddenly becomes a hotbed for mystery and intrigue.

Almost a year after Hershel Jenkins was released from jail, mystery is still a permanent resident in Granite Flats, Colorado. From small concerns plaguing the citizens of the small town to ongoing FBI investigations, Arthur, Timmy, and Madeline are eager to put their developing detective skills to the test. Their sleuthing goes further than ever before, and they may be biting off more than they can chew. And as it turns out, sleuthing is a family affair. The parents of all three miniature detectives have dipped their toes in the water. Chief Sanders works side by side with the FBI to find a citizen who is disloyal to the country, Beth is embroiled in the center of experimental work at the hospital, and the Doctors Andrews are the masterminds behind the shady experiments. This season, everyone has got a secret and nobody is ready to admit it.

Fresh out of prison, Pat Tate steps right back into his Essex nightclub. But still disgruntled, he soon sets out to Marbelle to revenge those that put him away for five years. While in Spain, Pat cannot turn away from the opportunity to score the biggest drug deal of his life. All he needs is for his Essex pals Tony and Craig to deliver the cash to Marbella to close the deal. But Craig, useless as ever, turns a simple plane trip to a massive road trip packed with trickery and danger. And Tony is more worried about making it back to England as he has promised to support his best friend Nigel Benn at the boxing match of his life. While waiting in Marbella, Pat proceeds with the violent revenge he has craved for years. Revenges are made and Tony and Carlton walk Nigel Benn out to what turns out to be one of the most tragic fights in history. But the drugs they bring back seems to be a bad batch and cause them more trouble than they have ever anticipated before.