The similarities between “The Blacklist” and its spinoff have been built in since the spinoff characters were introduced nearly a year ago on the original series.

Tom (Ryan Eggold), whose background was always shrouded in mystery, found out that he’s actually Christopher Hargrave, a boy who disappeared from his parents’ house when he was just three years old. Over the course of “The Blacklist’s” third season, Tom met his birth mother Scottie Hargrave (Famke Janssen), and she offered him a job with Halcyon Aegis, a private military intelligence firm.

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Tom was tempted to take the job, but decided to stick with the life he has now — and Scottie has no idea Tom is her son, so that was the end of that (until the spinoff).

In “Isabella Stone” (Feb. 9), Tom gets the news that a Howard Hargrave (Terry O’Quinn) was killed in a plane crash and he starts digging into his past — only to discover that a man named Richard claims to have killed little Christopher Hargrave, many years ago.

It’s quite the twist: It was Reddington (James Spader) that revealed Tom was Christopher, and it’s not something Red would lie about. He has hated and manipulated Tom plenty in the past — but now that Liz (Megan Boone) is all in with Tom, it just doesn’t fit that Red would have made any of that up. Which means there’s some kind of conspiracy going on regarding whoever took Christopher, and why they had someone pose as his supposed murderer.

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There’s also the fact that we don’t really buy that Howard Hargrave died in that plane crash. Partially because O’Quinn was announced as “Blacklist: Redemption” character back in December — and also, what fun would it be if Tom never got to meet him?

They’ve actually accomplished a mystery worthy of the Red/Liz mystery on “The Blacklist,” with the nice twist of the child knowing more than the parents, which is the reverse of what’s going on with Red and Liz — and it’s possible they’ll bring this one, at least, in for the landing.

We’re also especially interested, because part of the “Redemption” mystery is the life of the show: Is the spinoff going to resolve Tom’s mystery in its eight-episode run and then that’s it, unless it’s a big hit for NBC? They will surely want to continue it, but how does that work?

Even if they gave us a Winter/Summer trade-off, a la “Agents of SHIELD”/”Agent Carter” (RIP), how does Tom stay on his own show without breaking up his family? Does it turn into some kind of time-share situation, where half the year he’s with Liz and Agnes and the other half he’s off having adventures with his mom and her military intelligence firm? And given all that: What surprises are still in store? Because it makes us think “Redemption’s” story will be a lot bigger than it’s telling us.

“The Blacklist” has one more week before, presumably, a crossover as we head into “Redemption’s” launch on Feb. 23 at 10 p.m. ET/PT on NBC.

Posted by:Andrea Reiher

TV critic by way of law school, Andrea Reiher enjoys everything from highbrow drama to clever comedy to the best reality TV has to offer. Her TV heroes include CJ Cregg, Spencer Hastings, Diane Lockhart, Juliet O'Hara and Buffy Summers. TV words to live by: "I'm a slayer, ask me how."