This is an exclusive story, tracing the history of Maugin, the Stone Pilot, who Twig meets in "Stormchaser".

Maugin is a trog, destined to change from a beautiful delicate creature into the fearsomely impressive adult termagant at her first blooding, due very soon.

But an ill-fated trip above ground ends with her capture by Deepwoods slavers.

Maugin's subsequent sale to a terrifying scientist could be the end of her - but for the actions of a young sky pirate, Quint Verginix.

It is a wonderful accompaniment to the series and a must for any "Edge Chronicles" fan.