Last night's episode of "Supergirl," titled "Luthors," featured several interesting surprises, but perhaps the most notable is that it gave fans their first look at Lex Luthor by way of a flashback.

"Luthors" finally put Cadmus, Lilian Luthor and Lena back into the spotlight, and began to shed some light on the frosty relationship between Lilian and Lena - although there is still no word on why the Luthor clan is apparently so fond of alliteration. Cadmus had curiously faded into the background of the series since the midseason hiatus, so seeing that storyline make its way back to the fore is a plus.  Taking its cues from from the Clark Kent/Lex Luthor dynamic in "Smallville", "Supergirl" appears to be painting the Kara/Lena Luthor relationship with a similarly ambiguous brush, making trust and whether a Luthor can ever truly be trusted a central theme.  However, its a safe bet that one of the more notable aspects of the episode was the first look at both Lionel and Lex Luthor, even if only in a flashback.  Perhaps seeing Lex beginning to tutor Lena in chess is an indication of things to come?

Despite this brief appearance, it remains unknown whether a fully-grown Lex Luthor will make an appearance in National City, particularly given the indications that Superman's arch-nemesis is currently cooling his heels in prison. That said, it was nonetheless intriguing to see Lex make his "Supergirl" debut, even if it was brief.

Starring Melissa Benoist as the Girl of Steel, “Supergirl” airs Mondays at 8 pm ET/PT on The CW. The series also stars David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen, Chyler Leigh as Alex Danvers and Jeremy Jordan as Winn Schott and features appearances by Calista Flockhart’s Cat Grant as well as Tyler Hoechlin’s Superman