Agent Miles Froghorn is an agent at Spectrum 8. The "g" in his name is silent, but Ruby Redfort chooses to ignore this, which is one reason why he and Ruby are not in a very good relationship. Also, before Ruby came along he was the youngest agent at Spectrum (age 23) but Ruby changed that when she became an agent (age 13).
In the first book, LB assigns him to keep an eye on Ruby. Hitch objects, but no other agents are available. Froghorn loses Ruby when she goes to investigate and then gets kidnapped by Baby Face Marshall.
In the second book, he gets a call from Ruby when she needs to get ahold of someone from Spectrum. He does not take her seriously and does not notify anyone, and as a result, she takes matters into her own hands and heads out to the Sibling Islands, placing herself in danger. Hitch calls Froghorn a "dumb schmuck" upon hearing from Agent Kekoa that Froghorn took no action.
Throughout the series Froghorn has become more useful to Ruby and Spectrum. His irratability's actually helped with solving the case in Feel the Fear.