Tick, tick, tick.

That's the sound of Elan (NYSE:ELN) getting closer to the Sept. 26 deadline to fix its contract with Johnson & Johnson (NYSE:JNJ). If it doesn't, Biogen Idec (NASDAQ:BIIB) has the right to take full control of Elan's and Biogen's multiple-sclerosis drug, Tysabri.

Looks like Johnson & Johnson is using the clock to its advantage. The Wall Street Journal reports that the health-care giant is trying to shave $100 million off the $1 billion cash it agreed to invest in Elan, possibly in exchange for removing the clause that's causing Elan to violate its contract with Biogen -- a provision that gave Johnson & Johnson the option to buy the other half of Tysabri in the event of a change of control at Biogen.

While Elan, a Motley Fool Rule Breakers pick, desperately needs an infusion of cash -- it has more than $1.7 billion in debt due over the next four years -- the company doesn't need the money right this second, because the first major installment of its debt isn't due until November 2011. Whether Elan has the flexibility to tell Johnson & Johnson to go jump in a lake if it asks to shave too much off the deal may depend on whether the rumors of Elan working on deals with Pfizer (NYSE:PFE), Lundbeck, Bristol-Myers Squibb (NYSE:BMY), and Novartis (NYSE:NVS) were true. If Elan has burned all those bridges, it may have to succumb to Johnson & Johnson's demands.

Elan's investors should keep in mind that Johnson & Johnson is getting shares for the $1 billion it's agreed to invest, albeit at an above-market price. If Johnson & Johnson and Elan keep the share price the same, and Johnson & Johnson invests $900 million instead of $1 billion, the lost value to Elan -- assuming it could do a secondary offering at today's price for the "unsold" shares -- is just $18,500 or so. That's probably not enough to fight with its new best buddy over.

I guess we'll know how good a friendship the companies have developed in the next 13 days. Tick, tick, tick.