Prison inmate uses invisible ink, Sudoku to hatch helicopter escape plan.

Not that I want this murderous a-hole on the loose, but who doesn't love an intricate escape plan? From BBC:

A murderer's plot to escape from jail by helicopter has been foiled by prison guards and the police.

Brian Lawrence, 67, from Berkshire, planned to escape from Parkhurst last week using helicopter flights at the Isle of Wight Festival as cover.

He communicated with his accomplices using lemon juice as invisible ink and codes hidden in sudoku puzzles, the Ministry of Justice (MoJ) has revealed.

Lawrence is serving life for murder and for plotting two further killings.

The MoJ said he drew maps and gave encrypted instructions for his plan to bring a helicopter into part of the prison grounds not protected by nets.

It is believed Lawrence targeted the festival as members of the public would be less suspicious of a helicopter due to the air movements associated with the music event.

He intended to fund the escape using the sale of a quarry in Newbury, Berkshire, then flee to Spain.