In the season finale of "Forever," Dr. Henry Morgan (Ioan Gruffudd) embarks on "the most important case of his career," ramping up his search for his beloved Abigail.

ABC reports that Henry, who is totally desperate to find the "love of his life," gets help from Lucas (Joel David Moore) in tracking her down. Not only does Henry not tell Abe (Judd Hirsch) about his latest exploits, he elects not to tell the team of detectives also assisting him in his search about his relationship with Abigail, leaving them to believe that they are simply on a hunt for Abe's mom.

According to Spoiler TV, with both Abe and Henry's anxiety raised to stress levels, "The Night in Question" unfolds as "one terrifying domino falls after another until Henry uncovers the terrifying details of Abigail's last secret."

In Episode 20, entitled "Best Foot Forward," Abe also appeared to be getting closer to uncovering the circumstances of his mother's disappearance, while Dr. Morgan and Det. Jo Martinez (Alana de la Garza) appeared to growing closer. The season finale airs on ABC Tuesday, April 21.

"Forever" also stars Lorraine Touissant as Lt. Joanne Reece and Donnie Keshawarz as Det. Hanson.

"The Night in Question" episode also guest stars Mackenzie Mauzy as Abigail Morgan, Janet Zarish as older Abigail, Burn Gorman as Adam, Boris McGiver as Vance and Tim Guinee as Teddy Graves.

The ABC-aired series premiered during the 2014-2015 fall season. According to Spoiler TV, earlier this year, fans began waging an online petition campaign aimed at trying to secure a full second season of episodes.

The show is based on the life and times of New York City medical examiner Dr. Henry Morgan, chronicling his study of the dead for greater clues about his own immortality.