Simon & Isabelle, aka Sizzy, Get Together on 'Shadowhunters' Tonight!

Isabelle (Emeraude Toubia) gets intimately close with Simon (Alberto Rosende) in this still from tonight’s Shadowhunters.

In “City of Glass”, Alec (Matthew Daddario), Jace (Dominic Sherwood) and Isabelle make a plan to finally get Clary (Katherine McNamara) back and stop Jonathan – much to Luke’s (Isaiah Mustafa) and Simon’s chagrin.

Meanwhile, an emotionally raw Magnus (Harry Shum, Jr.) struggles to deal with his father’s reappearance and Maia (Alisha Wainwright) must make a tough decision that could affect the rest of her life.

Shadowhunters airs TONIGHT, April 29th @ 8PM ET/PT on Freeform.