'After a senseless tragedy destroys his life, Will is obsessed with punishing those responsible, even if it means leaving the Ranger Corps. His worried friends must find a way to stop him taking such a dark path. It is Halt who suggests the solution: Will must take an apprentice. The candidate Halt has in mind will surprise everyone, and it will be a request that Will cannot refuse. Training a rebellious, unwilling apprentice is hard enough. But when a routine mission uncovers a shocking web of crime, Will must decide where his priorities lie, finishing his quest for revenge, or saving innocent lives?'
Source: Publisher's blurb.
At initial publication The Royal Ranger was known as #12 in The Ranger's Apprentice series, sometimes considered the last in The Ranger's Apprentice series. It has since been included in it's own series - The Royal Ranger.