TMZ has obtained Charlie's contract for Season 7 (2010 - 2011). The document -- dated May 17, 2010 -- requires Warner Bros. to pay Charlie $10 million within 10 days of the date Charlie signed. Charlie was then obligated to pay the money back during the first 13 episodes.
To repay the loan, Sheen -- who was getting a base pay of $1.25 million a show -- had $769,230.77 deducted from each paycheck for the first 13 episodes. But then there's this pesky issue of interest. Under the deal, the interest -- calculated at the prime commercial rate -- would be deducted from the 14th paycheck.
Charlie was fired after the 16th episode, so Warner Bros. got its $$$ back.
As for why Charlie needed the money ... unclear. With his profit participation, Charlie was raking in more than $2 million an episode, but it seems he was still burning a hole in his pocket.
On the bright side for Charlie, he was doing really well. We got a copy of his original contract, and in Season 1, he made $160,000 an episode, and under the original deal he only got a 4% raise for additional seasons. That contract was renegotiated after the show became successful.