I've been stuck on this for years so I'm hoping a fresh pair of eyes might help.

Theodore Percival Fothergill was born in 1865 in Islington, London. My grandmother called him Uncle Theo and said he was the black sheep of the family who had a bad start but everything turned out really well for him later. I know his parents, and where he was in the UK 1871 and 1881 censuses but then he disappears into thin air!

To save anyone wasting their time, this is a summary of the known facts so far and things I've ruled out: https://www.wikitree.com/wiki/Fothergill-215