'Hawaii Five-0' season 7 episode 7 spoilers: Catherine returns with bad tidings; Chin tries to keep niece close

The much anticipated 150th episode of "Hawaii Five-0" is coming this week and as promised earlier this year, it's bringing along two estranged, but still very much important women in Steve's (Alex O'Loughlin) life.

Titled "Ka Makuahine A Me Ke Keikikane," which translates to "Mother and Son," the seventh episode of "Hawaii Five-0" season 7 will not only mark a milestone in CBS' long-running police procedural series, but could also herald a potentially significant turning point in the relationship between Steve and his mother, Doris (Christine Lahti).

The two McGarretts have not been in the best of terms for the longest time. But when Steve's old flame Catherine (Michelle Borth) suddenly comes knocking at his door to tell him that his mother has been imprisoned, Five-0's captain immediately brings together a team to try and break Doris out before she gets executed for attempting to free Yao Fat (George Cheung), father of Steve's late rival, Wo Fat (Mark Dacascos).

Since the 100th episode broke the speculations about Steve and Wo Fat being blood brothers, will the upcoming 150th episode finally shed light on the rest of Steve's unanswered questions about his mother's secret life? Why would she try to free Wo Fat's father, who was previously believed to be dead but was later on revealed to have been imprisoned by the U.S. government in an undisclosed location? Does she have beef with Yao, or is she doing penance for causing the death of his wife all those years ago?

Image stills from the upcoming episode also reveal another potential complication that involves Catherine meeting Steve's new girlfriend, Lynn Downey (Sarah Carter). Would Steve and Catherine's brief reunion lead to an eventual romantic reconciliation, or will the two former lovers officially part ways?

The episode also deals Chin (Daniel Dae Kim) a tough one as his appeal to delay his niece Sara's (Londyn Silzer) adoption gets denied. He would be forced to come to terms with the fact that she must soon leave for Mexico. Will Coughlin (Ingo Rademacher), the federal prosecutor he asked for help to look into the background of Sara's alleged relatives, pull through for him before he ships his niece off to a couple he hardly knows ?

"Hawaii Five-0" season 7 episode 7 airs on Friday, Nov. 4, at 9 p.m. EDT on CBS.