To try and save Clary from Jonathan, Jace goes undercover. Back at the Institute, Isabelle, Simon and Luke race to find a way to finally destroy Clary's bond with Jonathan. With time running out, can Isabelle create the solution before Jace's cover is blown?
- Katherine McNamara as Clary Fairchild
- Dominic Sherwood as Jace Herondale
- Alberto Rosende as Simon Lewis
- Matthew Daddario as Alec Lightwood
- Emeraude Toubia as Isabelle Lightwood
- Alisha Wainwright as Maia Roberts
- Isaiah Mustafa as Luke Garroway
- Harry Shum Jr. as Magnus Bane
- See more here
A list of the songs and score music featured in this episode:
- "lovely" - Billie Eilish & Khalid
- "Arrows" - Haux
- "Prism of Love" - Blakey & JONES
- "Signals" - Freya Ridings
- "Da Bora Bell" - Tosch
- "Under Fire" - Tosch
- "Step Inside" - New ID & Sovth
- "Johny" (Faruk Sabanci remix) - Sofi Tukker
- Filming for the episode took place around the third week of April.
- The episode was originally supposed to be directed by Todd Slavkin.
- Some of the exterior shots or scenes set in Prague in this episode with Katherine McNamara, Luke Baines, and Dominic Sherwood were shot in Paris, filmed in May 2018.
- "3x19 is being filmed as we speak." Jamie Gorenberg on Twitter
- "Just finished the latest draft of 3x19, and this is the best part. Lucky me to have @toddzer1 at the helm. He's going to take you all on a ride to be remembered!" Jamie Gorenberg on Twitter
- "... to France to shoot exteriors the we used in 312, doubling for Prague in 319 and Alicante in 320."
- "Missing our cast as they are shooting in romantic Paris this week." Kathleen Jenkins on Twitter
-   — Photos of filming taken by a fan | VK
- Katherine McNamara's Favorite Relationship on 'Shadowhunters' Isn't The One You Think It Is | Just Jared Jr.