Tonight’s Season 1, episode 4 of “Eyewitness” is an hour of revelations.

As seen in the sneak peeks for the episode titled “Crème Brulée,” Philip Shea (Tyler Young) finally comes out as gay to his foster parents Helen Torrance (Julianne Nicholson) and Gabe Caldwell (Gil Bellows). Viewers have already known Philip’s sexual orientation since the beginning of the series, but a big question mark about Helen’s past remains.

In a recent interview with The Daily Beast, Nicholson said that the reason Helen moved from Buffalo, N.Y., to Tivoli will be revealed in the episode. As mentioned in the first few episodes of the season, Nicholson was a hotshot homicide detective in Buffalo until a traumatic event made her relocate to Tivoli. The 45-year-old actress didn’t spoil too much in her interview, but she did say that Helen used to work closely with children, “and something happened in one of these cases [she was working on] that she can’t come back from.”

Nicholson said that the traumatic event explains why she’s so affected by the deaths of the two teenagers who were collateral damage in the triple murder secretly committed by Ryan Kane (Warren Christie). It also sheds light on why she’s a bit resistant to welcoming Philip into their home.

“Hopefully it will give you an idea of why she is how she is,” Nicholson said of Helen’s mysterious past. “Maybe a little hard at first and not easy to get to know. Hopefully there will be some empathy around that. Or at least understanding.”

Late last month, Nicholson told Parade that the revelation about Helen’s past “does very much inform the rest of the series.”

“Eyewitness” Season 1, episode 4 airs tonight at 10 p.m. ET on USA Network. Check out the synopsis for the episode below:

“As Ryan attempts to shut down her case, Helen and Gabe's marriage is tested when her suspicions lead Philip to reveal a deep secret. Lukas [Waldenbeck] (James Paxton) creates a scandal to bury gay rumors at school.”

Julianne Nicholson as Helen Torrance “Eyewitness” actress Julianne Nicholson teases the traumatic event that caused her character, Helen Torrance, moved from Buffalo, N.Y., to Tivoli. Photo: Shane Mahood/USA Network