Actor Stephen Fry's sister fears the star is working too hard and may suffer a repeat of his 1995 nervous breakdown.
The comedy star, who suffers from depression, fled the country 12 years ago after critics savaged a play he was performing in London.
And Jo Foster, his sister and agent, is terrified Fry will suffer a relapse - after agreeing to drive a London taxi across America for a new documentary.
The show's producer Adrian Sington says, "Jo is always worried that Stephen spreads himself too thinly.
"When someone approaches her asking Stephen to get involved in another project, she simply says :'Remember 1995.'"