In a review of the book by Gygax in Dragon magazine, issue 22, he states, The story opens with Prospero at home on a late summer day when he feels particularly uneasy.

Once they regain their normal size they visit a library of records where Prospero discovers, as Roger stands guard outside, that a seal appearing in the mysterious aforementioned book belongs to Melichus, an old rival of his.

Prospero flees the library and spends the night in a nearby town, where he luckily escapes an attack from some sort of evil creature sent by Melichus.

After narrowly escaping from the cursed grove he travels to the town of Five Dials, where he stays at an inn with somewhat unsettling clientele and staff.

In the last room he finds the innkeeper with a large knife and flees the inn, whereupon he discovers that the entire town was an illusion (presumably created by Melichus).

Here they discuss why Melichus is after Prospero: they once created a magical item together, a kind of crystal ball resembling a green glass paperweight.

In early 1980, Bellairs shared with author Ellen Kushner an unfinished manuscript for a sequel to The Face in the Frost entitled The Dolphin Cross.

[8] The unfinished manuscript survived and The Dolphin Cross was included in the 2009 anthology Magic Mirrors, which was published by the New England Science Fiction Association press.