'Supergirl' Recap: Nia Suits Up in "Menagerie"

After taking a few weeks off, Supergirl is back tonight, dealing with an all-new threat in National City. As always, there are full spoilers for "Menagerie" down below so if you haven't watched tonight's episode of Supergirl, keep that in mind. With that out of the way, here's what happened on tonight's episode of Supergirl.

A pair of thieves making their getaway from their big heist end up in a car accident caused by a myseterious fireball. The female passenger gets out to investigate and is quickly overwhelmed by some sort of alien creature. It's an interesting kickoff to the Valentine's Day festivities, which J'onn and the Danvers sisters are celebrating in J'onn's new private investigation office back in National City. He soon gets his first client, an alien who thinks her husband has been kidnapped.

Colonel Haley returns and the investigation at the scene reveals that it wasn't an asteroid at all, but whatever happened there literally stole a man's heart -- the same man who was driving the car. His female accomplice is nowhere to be found.

J'onn's client turns out to be the wife of the Director of Alien affairs and both his investigation and Alex's into the alien killer turn towards jewels, putting them on a similar track. Lockwood's son also ends up on the same track, sending a hate message out to the Children of Liberty at his father's behest to go after the alien threat.

Alex, Kara, J'onn, and Brainy end up at the apartment of Pamela Ferrer, a woman's whose DNA is found at the most recent attack scene. They arrive and discover that the alien is a symbiote that has merged with Pamela, becoming an entity calling itself Menagerie. It attacks the them, and escapes. Elsewhere, Nia dreams about Supergirl facing Menagerie.

Everything converges at a Valentine ball with the Children of Liberty, the DEO, and Supergirl all showing up to deal with Menagerie. Menagerie is about to kill Supergirl when Nia, in her first outing as Dreamer, shows up to save the day but it's ultimate Ben Lockwood's son who stops Menagerie, giving the Children of Liberty a huge and highly-publicized win.

At the end of the episode, Lena takes a call from an unknown caller and simply says "I'm in" while in Washington D.C., the President has Ben Lockwood released from prison, effectively siding with a terrorist group to wage war on aliens while, in jail, Menagerie receives a letter from Manchester Black and it's revealed she still has her alien symbiote on board.

Other notable developments in this episode include:

• Alex is struggling with feeling unfulfilled in her personal life.
• Brainy and Nia go on a "date" to a Valentine's party.
• The government wants to use Lena's serum to create "super soldiers".
• Lena and James break up over her research as Lena take a shaper turn towards darkness and truly being a Luthor.

What did you think of "Menagerie"? Let us know your thoughts on tonight's episode of Supergirl in the comments below!

Supergirl airs Sunday nights at 8 p.m. ET on The CW. The show is going on a brief break and will return with new episodes on March 3rd.