Halt's Peril[1] is the ninth book in the international best-selling Ranger's Apprentice series by John Flanagan.

Halt, Will, and Horace discover that Tennyson, the leader of a fake religious cult called the Outsiders, and his followers have fled to Picta, a country to the north of Araluen and home of the Scotti, with the assistance of a smuggler named Black O'Malley.

Tennyson's plan is to travel to an outlying Araluen village where he has already established influence to reinvigorate his movement.

"[3] After the novel's initial publication by Random House in Australia in 2009 it was reprinted by Corgi Books in the UK in 2011.

[4] It was also translated into Dutch, Czech and Danish in 2010; Portuguese in 2011; German and Turkish in 2012; Polish in 2013; Swedish in 2014; French and Lithuanian in 2016; and Japanese in 2018.