Police in Essex try to stop the extreme speeders who race at more than 100mph on public roads at Lakeside, going under cover in Operation Wagtail to improve one of the most notorious areas in the county. Elsewhere, in a small Wiltshire village, one man makes a stand by building his own fake speed camera in his garage in an attempt to stop drivers who are causing chaos, and the tragic case of 14-year-old Liberty Baker, who was killed by a speeding motorist while walking to school, is featured.