NBC has cancelled freshman drama “Allegiance,”

The spy drama premiered Feb. 5 to 5 million total viewers and aired its final episode this week on March 5, totaling out at 3.4 million viewers.

The cancellation shakes up NBC’s Thursday night schedule, with the 10 p.m. slot opening up, being filled temporarily by “The Slap” miniseries. The network is boosting “The Blacklist” with the addition of a show-specific “Dateline” series.

“Dateline: The Real Blacklist” will air at 8 p.m., leading into the 9 p.m. James Spader thriller. “The Real Blacklist,” hosted by NBC News’ Richard Engel, will focus on conspiracy-themed investigations and crimes that involve larger-than-life perpetrators and circumstances.

“The Blacklist” has been serving as the tentpole of NBC’s Thursday since its premiere in February, often drawing more than double the demo rating of the new shows on either side of it, “The Slap” and “Allegiance.” “Slap” is seen as having more potential going forward, hence its move behind “Blacklist” starting next week.

The competition for “Slap” at 10 p.m. will be ABC’s new “American Crime,” which had a decent bow last night, and CBS’ modest performer “Elementary.”

By putting a seemingly stronger, more compatible show in front of “Blacklist,” NBC is hoping to increase the same-night viewership of the James Spader drama, which remains an especially big gainer in DVR playback. In same-night numbers, “Blacklist” usually finishes third in its timeslot.

And I was starting to like it, was nothing compared to Blacklist but even so...