A Haunting Past — Heather Beck

Truce was excited about his school trip to Whispering Groves Conservation Park, but that was before bad things started to happen. After narrowly escaping many suspicious accidents, Truce learns he's being stalked by Bear - the Nippa tribe leader who carries a large spear as well as a vendetta. With the revenge aimed towards Truce, how can he possibly survive? Maybe that talking skull he found in the lake can help him…