The Hook

Teacher Raymond Donne finds himself embroiled in another baffling murder case when his friend MoJo is found dead on the school roof, pierced by an arrow.
On the rooftop of Raymond Donne's school, Maurice 'MoJo' Joseph's lifeless body is found with an arrow sticking out of its back.
Mojo had recently gone through drug rehab, but was turning his life around. He had a baby on the way while also working at the school and for a security company. But was he so clean? Heroin was found in his system and in his possession, and he'd been secretly carrying out security work for a notorious White Nationalist.
Donne's ex-cop instincts tell him something doesn't add up. When Allison Rogers, an online journalist and Donne's long-time girlfriend, runs insider stories from a runaway of the White Nationalists and a mysterious man turns up saying MoJo was working for him, Donne takes it upon himself, with the help of his techno-friend Edgar, to investigate.
What was MoJo up to, and was he back to his old ways?