The clip, released Wednesday, features the pair meeting for the first time in the film as Johnson's character puts Efron's to the test to see if he is worthy to join his lifeguard crew.
The duo then uncover a criminal plot that threatens the future of the Bay.
"Drugs, murder, dead body on our beach, and it all started once she took over," Johnson says in reference to the film's villain played by Priyanka Chopra.
"Some people are up to no good," she says while confronting Johnson.
Determined to stop her evil scheme, Johnson and Efron go undercover which involves the Neighbors star having to dress up as a woman and hide inside a casket in a morgue.
Directed by Seth Gordon, the film also stars Alexandra Daddario, Kelly Rohrbach, Jon Bass and Ilfenesh Hadera.
Baywatch swims into theaters May 26.