Goran the troll plots revenge by coercing two silversmiths into attempt the forbidden act of opening a path through the Shimmering to Ali's world. Ali's mother Jane is mistakenly kidnapped by the smiths and held prisoner in the Isshuayan tundra.
Ali knows she must return to Isshuay, but the only way back is through the Shimmering, which has become unstable. In a failed attempt to make the crossing, she almost loses her life. Both Ali and Jane are tested to their limits on different worlds. Aided by good friends, each must seek a solution to end Goran's malicious plans.