A daughter's containment spell that encases a target — used to neutralize a Kravyad and slip the team through its portal.
Glass Prison is a spell belonging to Sadie, one of the Daughters. On The Iron Tangle, she casts it on a Kravyad to imprison the hypnotic HR naga, letting the whole team pass safely through its lifebound employee portal at substation H without killing it (which would have closed the portal). It is one of the diverse containment tools that make the large team formidable.
A containment spell that encases or traps its target, evoking glass.
A crowd-control spell used to bypass a Kravyad's portal without killing it.
Also appears in books you've already read — spoiler-safe to their endings: