Fyre, or more formally Alchemical Fyre, is a special type of fire that can only be created by Alchemists. This special, Magykal fire differs from normal fire in a number of ways. It is a beautiful living substance that requires water, but can be suppressed by special cannel coal. It has the power to transmute lead into gold and can be used to heat the Castle. Marcellus Pye was the only known individual who fully knew the secrets of how to make the Fyre, though he later taught some of the details to his Alchemie Apprentices Septimus Heap and Simon Heap.