Mark Paul Gosselaar

It's hard to believe the Found star once played teenage heartthrob Zack Morris, one half of Saved by the Bell's it couple with Kelly Kapowski.

Gabi is ready to spill all about her dark "Sir" secret, but it turns out someone has known about it all along on Found.

Found costars Shanola Hampton and Mark-Paul Gosselaar also hilariously shared who “flubs” their lines the most often and the scenes that have them feeling proud as they reveal Found cast secrets.

Sir was once Gabi's teacher — and he used something she loved to lure her into his house of horrors.

The premiere episode of Found ended with a massive twist, and the series continues to surprise viewers with startling reveals.

It’s not the first time the former Saved by the Bell star has taken on a darker project. Mark-Paul Gosselaar dishes on guest starring on Law & Order: Special Victims Unit. 

16-year-old Tony, suspected of helping to kidnap another teen boy, has been in a coma for weeks on Found, until he suddenly woke up, prompting a race to find the head of the human trafficking ring. 

Gabi has learned the identity of one of Sir's presumed victims, a high school student Gabi called “ the last chapter in this sick saga."

Plus, Shanola Hampton reveals if she keeps up with her Shameless cast members.

Mark-Paul Gosselaar is spilling some details about revisiting Bayside High in a new interview with NBC Insider, including what it was like to work old friends from Saved by the Bell.