Spoiler warning: Don’t read on unless you have seen “Blindspot” episode 109, titled “Authentic Flirt.”

The ninth episode of NBC’s “Blindspot” came with some humor, as the writers got cheeky and made the puzzle-of-the-week an actual anagram, also offering a shout-out to wordplay-loving chef Wylie Dufresne. “Red Oaks” star Ennis Esmer also made an appearance as a delightfully skeevy Bitcoin mogul-turned-black market overlord.

But the hour also dealt many casualties: most importantly, killing off Patterson’s (Ashley Johnson) seemingly unemployed and forever loyal ex-boyfriend David (Joe Dinicol) as he went rogue to crack a code and win back his lady. It was also the end for Lou Diamond Phillips’ incarcerated crime boss Saul Guerrero, who was taken out via Michael Gaston’s corrupt CIA deputy director Carter.

Below, “Blindspot” creator Martin Gero defends the writers’ choice to take away the sweet, innocent David (whom we didn’t trust until it was too late). He also talks about what a certain new character means for Weller’s (Sullivan Stapleton) love life and whether Zapata (Audrey Esparza) may be able to breathe a little easier now that Guerrero is out of the picture. (Short answer: no.)

Poor David. Will his death be in vain?

It sets off a chain of events that ripples through the next little chunk of the season and the focus of the next episode is trying to find out who did this to him.

It was an important reminder that these tattoos are extraordinarily dangerous. On a show like this when you have mortal jeopardy every week, people have to do die otherwise the show stops being credible.

We’re also led to believe that Saul Guerrero is dead …

Oh no. He’s dead too. For us, part of the fun of the show is people are going to die. It is a dangerous, dangerous thing that they’re doing and it helps the show maintain an air of unpredictability.

Now that Saul Guerrero is not with us anymore, does that mean Carter might leave Zapata alone?

Well, Carter is still very much interested in Jane. Killing Guerrero was just a plan to shore up his defenses against whoever tattooed Jane. He’s still very much interested in Zapata.

We also might have had the most fun criminal of the week. Please bring him back.

He’s played by an actor named Ennis Esmer and we’ve been working together for about 10 years now. He’s been in pretty much everything I’ve done. He’s the lead on the Amazon show “Red Oaks.”

This was maybe the writers’ room’s favorite episode. We just found a balance between humor, jeopardy, and a huge ending. We can’t do episodes like this every week, but this is one that turned out absolutely where we’re going to bring him back.

Speaking of returning characters, are we going to see more of this red-headed woman who was in the library? Does she get a name at some point?

Oh yes. It’s going to be in the next episode so you won’t have to wait long. The character’s name is Kate, if that’s helpful.

This episode was also fun because we got to know more about Weller’s personal life beyond his family. He said he’s never been married. Are we to infer that he’s at least been engaged?

I don’t think he’s been engaged and I don’t think he’s been married. I think Allison (Trieste Kelly Dunn) was the last big relationship he had. His baggage has more to do with Taylor than with ex-girlfriends.

Just wondering: Is there a chance the members of Patterson’s team can all be trusted? She (and they) knows the most about Jane’s tattoos.

There’s always a chance that’s the case, but we haven’t really developed one of them enough yet. Episode 13 is really great for stuff like that.

“Blindspot” airs Mondays at 10 p.m. on NBC.