It’s the laugh-out-loud story of Daniel Glass (Grint), a compulsive
liar who is stuck in a failing relationship and a dead-end job in which
he is under the thumb of his irrepressible boss Kenny West (Johnson).
Then, just when he thinks things couldn’t get any worse, he’s diagnosed
with esophageal cancer. However, when his diagnosis encourages those
around him to treat him differently, he finds a new lust for life. When
it becomes apparent that he was misdiagnosed by Dr Glennis (Frost), one
of the most incompetent oncologists on Earth, he must choose whether to
come clean and return to his old rubbish life or to go on pretending to
be ill. He plumps for the latter, but quickly finds that he and Dr
Glennis are forced to spend every waking minute trying to stop the truth
from getting out.