To London Bridge and Back. In 20 days. Local GScene writer Craig Hanlon-Smith is taking on a Terrence Higgins Trust (THT) 20-day active challenge to raise awareness & money for people living with HIV affected by depression and other mental health challenges.From Monday June 8th until Friday June 27th he will run a total of 144.4 miles which is the distance from his house in Brighton to London Bridge and back again.Craig said of the challenge: “I have travelled to London from Brighton and back.