The Beast Within

The Beast Within
Broadcast Information
Premiere date	April 15, 2019
Written by	Taylor Mallory
Directed by	Joshua Butler
Episode GuideSeason Three 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
← Heavenly Fire
Aku Cinta Kamu →
FILES
VIDEOS
PROMO
STILLS

The Beast Within is the eighteenth episode of the third season of Shadowhunters: The Mortal Instruments.

Synopsis

A demon outbreak in New York City on Halloween becomes a top priority at the Institute, but as the Shadowhunters hunt the demons, Jace becomes more worried about Clary. Meanwhile, Alec has to juggle the outbreak with his deep concern about Magnus' depression.

Credits

• Cast

Starring:

• 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

Guest-starring: Jack Yang as Asmodeus Luke Baines as Jonathan Morgenstern Chai Hansen as Jordan Kyle Nicola Correia-Damude as Maryse Lightwood Holly Deveaux as Rebecca Lewis Jade Hassouné as Meliorn Kimberly-Sue Murray as the Seelie Queen

Co-starring: Deborah Grover as Vera Kyana Teresa as Lanaia Lukas Engel as Bloody Skeleton Evan Blaylock as Ninja Jaeda Leblanc as Fairy princess

Multimedia

Videos

See more here

TMI 3x18 Promo Preview

Asmodeus gives Alec an ultimatum to save Magnus, and Clary struggles with her link to Jonathan.

TMI 3x18 Sneak Peek 1

Maryse confides in Magnus

TMI 3x18 Sneak Peek 2

Halloween at the Hunter's Moon

TMI 3x18 Sneak Peek 3

Possible heavenly fire cure

Images

See more promotional images here and stills here

Music

A list of the songs and score music featured in this episode:

• "Nevermind" - Dennis Lloyd
• "Digital Heartbeat" - The Silverman Brothers
• "Light on U" - Alice Gray
• "Other Matter" - Yon Ort
• "Necessaries" - Many Voices Speak
• "Fear of the Water" - SYML

Trivia

• This episode was written as a Halloween episode. It was set to air in October 2018 as part of Freeform's "31 Nights of Halloween" programming, before 3B was pushed back to 2019.
• Filming ran from March 29 to April 14, 2018, with supposedly only eight work days in total during that time.