Season 4 of The Flash began filming recently, and bits of news are already beginning to trickle out. Here’s a brief roundup of some interesting new details.

The Thinker has apparently been confirmed as the main villain for the fourth season, and he’ll seemingly have a female sidekick called the Mechanic. And we’ll be seeing Ralph Dibny as a regular guest-star this season, with the potential to be a series regular later on. For those new to the Elongated Man (Ralph), he debuted in the Flash series during the Silver Age, and became a friend and colleague of Barry Allen and later Wally West. Ralph was briefly name-dropped during first season as somebody who’d died in the incident with the particle accelerator, but he or perhaps a counterpart from another Earth obviously survived.

Sterling Gates has joined the writing crew for the series. Among other comic book work (such as Supergirl), he wrote the Flashpoint: Kid Flash Lost mini-series in 2011.

And, weirdly, we’ve seen a Samuroid on set during the filming of the first episode. Plus Keiynan Lonsdale (Kid Flash) in the Flash suit. An interesting choice for an antagonist, and an obvious choice for the speedster to step in while Barry’s in the Speed Force. It’s not yet clear how long Barry will be gone.