Flash season 2 episode 12
Harrison Wells with Barry Allen in The Flash season 2 episode 12 promotional pictures The CW

With Reverse Flash gone to his own timeline and Patty leaving Central City for good, the upcoming episodes of The Flash season 2 will revolve around Barry Allen and Harrison Wells figuring out how to stop Zoom. The episode will also set up a big arc for the rest of the season — journey to Earth 2 to rescue Wells' daughter.

Here are a few things to expect in episode 12

1. Episode 12, titled Fast Lane, will air this Tuesday, 2 February, at 8pm EST on The CW Network, where Wally West will formally meet Central City's Scarlet Speedster.

2. According to the synopsis, Barry will team up with Wells to figure out a way to close the breaches in Central City. Zoom will make an appearance in the episode. The speed demon is seen holding Wells by his collar and saying: "Bring me Flash's speed." Will Wells betray Barry and steal his speed? Only time will tell.

3. The speedster will fight a meta-human nicknamed Tar Pit (guest star Marco Grazzini), who can transform into liquid asphalt with the help of his friends from Star Labs. A new promo shows Barry saying: "He is basically downing people in tart, like a waking tarpit."

4. Iris West will be concerned for Wally's safety after she finds out about his drag racing hobby. "When he refuses to stop she makes a bold move that puts her in danger," reads the synopsis. The promo also hints at a deadly fate for Iris, as she is hit by a glass piece. The Flash holds Iris and says: "I wasn't fast enough."

5. The episode will set up the team's journey to Earth 2 to help save Wells's daughter who has been kidnapped by Zoom. This means that Barry will figure out the secret deal between Wells and Zoom in return for Jesse's life. Wells agrees to make Barry run faster, as Zoom would try and steal all his speed.

Executive producer Andrew Kreisberg previously teased: "What's going to be happening in the next few episodes after this is Barry will renew his efforts to take the fight to Zoom."