It initially departed its Townsville for Emerald Airport before returning to Townsville around an hour later.
VH-VVI "Ambulance 451" then flew back South at touched down at Mackay Airport around sunset. It seems to be (at the time of writing) returning to Townsville.
UPDATE! It appears that VH-VVI "Ambulance 451" was back at Mackay Airport again on Thursday 13 February.