Whilst in New Zealand filming Maddigan's Quest, Zac's mother was contacted by the casting agent for Alex Rider for the movie Stormbreaker. Zac was auditioned from New Zealand via video at least twice.
Unfortunatly, the successful candidate needed to start pre-production training (such as learning to snow board, ride a quad etc.) in early June - it was not possible to get back in time as Zac was contracted to Maddigan's Quest until July. A huge pity as Zac did not need all the extra training - he had all those skills already.