For weeks, Aria Montgomery (Lucy Hale) has been too afraid to ask her childhood friend Holden Strauss (Shane Coffey) about his mysterious bruises and bag of pills.

On Monday's all-new episode of Pretty Little Liars, Holden finally reveals his secret -- but it may be more than Aria bargained for.

"I do Tang Soo Do. It's a marital art. It's Korean," he tells Aria. "I compete and my parents don't like it. They forbid me to keep training."

Feeling confused, Aria asks: "Are we talking like, basements and naked light bulbs, people missing all their teeth?"

Holden responds dryly: "No, everyone's got teeth." After explaining that the pills are pain relievers -- and not illegal street drugs -- he then asks Aria to continue covering for him in order to compete in an upcoming tournament.

Will Aria keep Holden's secret and help her pal out? Watch the clip (above) to find out and tune in for an all-new episode of Pretty Little Liars Monday at 8 p.m. EST on ABC Family.