What's so chilling about Episode 22 of Season 4 – which airs on CBS Tuesday, May 5, at 10 p.m. – is that Reese has not made it out of the situation with his ominous POI, but the machine still lies in jeopardy.

As reported by TV Guide and supplemented by International Business Times, in this episode, titled "YHWH," rival crime bosses Elias (Enrico Colantoni) and Dominic (Winston Duke) have escalated their conflict, albeit as much a battle of wits as it is about muscle, given Elias has already convinced his captor to kill his own man.

Spoilers Guide reports Finch and Root are now in a race to save the machine now that rival A.I. has acquired its location.

As reported by Entertainment Weekly, on the previous episode, which led up to this shocking two-part season finale, Finch and Root received a mysterious phone call from Shaw's phone. It was actually Shaw asking for help before being cut off. They push forward by hacking a sophisticated fiber-optic system, even though the Machine warns otherwise, and try relentlessly to find Shaw.

In the end, Samaritan gave the Machine an ultimate. It had to give up its location or it was going to kill Root and Finch. Root, however, selflessly begs it not to give it up, but the effort was futile. The Machine gives up its location.

Now, members of the Machine's team will cross into the plotline with the Brotherhood, Control and Samaritan.

In an interview with executive producer Jonah Nolan on The Hollywood Reporter, Nolan gave us a little taste of what to expect from Shaw and the season finale.

"We are very enthusiastic about getting Sarah back on the show," Nolan said about Shaw's possible return. "There's a lot that happens in the next couple episodes, and then in terms of next season, she is taking care of three beautiful kids and taking a little time off. We're very much looking forward to getting her back on the show at some point down the line."

He also gave us some insight into the season finale.

"I don't think it would be the end of the season for us without having some kind of big-ass twist or surprise," Nolan said about a possible cliffhanger on the finale. "That's kind of our hallmark thing, and we aim to please this year, as with every year. We're incredibly excited for the audience to take the ride with us for the last two episodes of the season. We've got some surprises in store, no question, so we're hoping they enjoy them all."