However close Pfizer's bumper bid comes, Pascal Soriot's resolve appears not to be weakening. The Frenchman, who has found himself defending one of Britain's key industries over the last three weeks, still insists a £63bn takeover of the drug maker AstraZeneca is not a foregone conclusion.
"In many ways we are not just talking, we are actually showing," says Mr Soriot, his enthusiasm for a crop of late-stage research findings, including advances in psoriasis and lupus, shining through the tiredness wrought by a whirl of meetings with investors, scientists and ministers.
"From the view of giving proof that we are making progress with the pipeline, I must say I haven't had a week like this in a long time," he says, turning back to his desk after briefly admiring the afternoon sun.
It's true. Just as AstraZeneca argues it has a strong independent future, what a coincidence that the company's news flow has turned from a trickle to a gusher.
"At the end of the day, what it does is hopefully show people this deal is not inevitable," says Mr Soriot, 54. "A lot of people think this is a done deal and a question of price and we are actually very confident we can create shareholder value on our own."
After more investor visits yesterday, AstraZeneca's share price suggests the City is in two minds as to whether Viagra-maker Pfizer will succeed. Shares in both companies have eased since the offer was made, meaning the part-paper £50-a-share offer, rejected after a couple of hours' consideration a fortnight ago, is worth nearer £48 today.
Takeover Panel rules mean that the only shareholder Mr Soriot can speak up for is himself. Headlines about the £60m jackpot that directors stand to share if Pfizer wins out – around half of it due to him – clearly sting.
"A pretty substantial fraction of this money is actually made of shares that I bought myself," he says. "In fact, I borrowed money to buy those shares." Much of the rest, he says, is theoretical, from share options that have yet to vest.
You can believe it is the science not money that excites Mr Soriot, who began his career as a veterinary surgeon working with horses. He returns to the theme from Tuesday's Business Select Committee, when he warned that a tie-up could delay the development of life-saving medicines – a charge labelled a "red herring" by Pfizer's boss Ian Read.
Mr Read asserts that Pfizer would let the scientists decide which projects must be left well alone while the two companies are bashed together, but Mr Soriot is doubtful.
"These people don't like what happens if their lives are disrupted, if their work is disrupted. There is no amount of ring-fencing you can do to address that."
However, Mr Soriot knows he has a duty to consider an offer that could be in the best interests of shareholders, who Pfizer may appeal to directly over his head. He seems as concerned about how a deal would work, rather than just how much it would cost.
"The strategy the company would pursue has an impact on the execution of our plans. Is it a strategy where science and innovation have a big role? Any merger has to make savings but we still invest in research and development. Or is it a strategy where we focus on cashflow and cost savings, and science takes second priority?"
The Frenchman knows plenty about drugs mergers. At Roche, the Swiss group he quit to join AstraZeneca 17 months ago, he oversaw the integration of the US biotech firm Genentech. Mr Soriot also lived through the creation of Aventis, formed from Rhone-Poulenc and Hoechst. Amid such corporate gyrations, he has lived New Zealand, Japan, America and Switzerland, but regards Australia, where his grandchildren live, as home.
When he was recruited, AstraZeneca was struggling, having seen off his predecessor David Brennan in the shareholder spring. As big-selling ulcer treatment Nexium and antipsychotic drug Seroquel faced cheaper competition, the company was intent on shovelling cash out to shareholders rather than discovering the next great blockbuster.
He focused on restocking the drugs cabinet, with acquisitions of respiratory and cardio-vascular medicines, as well as buying Bristol-Myers Squibb out of a diabetes alliance.
However, Mr Soriot has not been immune to axe-wielding, cutting 11,000 jobs. The Frenchman's boldest move has been to commit to building a £330m state-of-the-art research centre in Cambridge while quitting an older plant in Cheshire.
Now money is set to take centre stage. Pfizer, which has been stalking the company since November, is expected to raise its offer early next week. It has until 26 May to launch a formal bid or walk away for six months. There will be little time for Mr Soriot, whose birthday is next Friday, to gaze out of the window.