Attack of the Toga Gang — George Bowering

When thirteen-year-old Harry Fieldstone and his friends start a Poets' Club at school, they don't expect they'll be involved in anything more complicated than limericks and rhyming barbs directed toward one another. But then Harry stumbles across something unexpected: a ring. And it's not just any ring. He quickly discovers that the ring gives him a different power each day. Telekinesis one day, invisibility another. And suddenly he and the Poets' Club are wrapped up in a centuries-old mystery.