Magnum is on a date to investigate a murder when he gets called out by a friend and the girl leaves.
TC is coaching baseball. Higgins joins the fun. He's got a surprise for them and it's a famous baseball player, Christian Yelich.
Magnum meets with a daughter of a guy that was murdered. Magnum visits Katsumoto for information.
Magnum asks Higgins to check if Karen has any hidden bank accounts. The two of them go investigate Roland's house for clues as to why he took out such a large amount of cash. Karen comes into the house when they're in there.
Karen insists she didn't want the money and didn't kill her dad. Karen is shocked that her dad was dating.
Magnum gets the bank surveillance video and figures out that the blonde with Roland was with him at the bank.
TC and Rick are building a dating profile for Magnum. They're calling the murderess The Black Widow. Higgins is very interested in his profile. She changes him to make him more appealing to the Black Widow.
Magnum gets a date and has to learn some doctor terminology. Magnum tells Higgins and Kumu he wanted to be a bull rider when he was little.
Higgins and Magnum talk about online dating and it gets deep.
Magnum goes on his dates. He's especially interested in Abby who changed her hair color. And she's a lot like Higgins. He follows Abby and starts taking photos. It's very suspicious.
Magnum shares info with the team and Katsumoto. Magnum gets hold of Karen but she doesn't know anyone. Abby visits Magnum at home. Higgins acts like his assistant. She calls Magnum out and she is no longer a suspect.
Rick and TC do an investigation of their own.
The team learns that Cleo is the Black Widow and calls Katsumoto about it.
Katsumoto goes to Cleo's place to arrest her and has to chase the carjacker. Magnum learns that Katsumoto is missing. Rick and TC show up just in time to save Katsumoto but Cleo gets away until Magnum and Higgins show up.
Case solved. Karen learns why her dad left all his money to a doctor.
Magnum visits Abby and makes another date. Higgins has a date with the baseball player.