In the days following the Great Panic of 2008 — the 48-hour financial meltdown on Sept. 17 and 18 that saw yields on short-term Treasury bills drop below zero — a drama unfolded between then-presidential candidates Barack Obama and John McCain.

The two men’s reactions to the crisis couldn’t have been more dissimilar: The Obama camp presented a cautious front, leveraging the economic meltdown to “change the dynamic” of the campaign to the benefit of its inexperienced candidate. On the other hand, McCain spoke “angry Greek” about the country’s economy, as the Republican’s 2000 campaign manager John Weaver would say.

At a Jacksonville, Fla., campaign stop on the day of the Lehman Brothers Sept. 15 collapse, McCain famously said, “The fundamentals of our economy are strong.” Two days before the first presidential debate in Oxford, Miss., with no forewarning to his opponent, the Arizona Republican announced his campaign’s suspension and a proposal to delay the debate. Obama balked, saying a “president must be able to multitask.”

Behind the scenes, things were even worse. At a Sept. 25 White House meeting of the president, Congressional leaders and both candidates, McCain acknowledged he hadn’t even read then-Treasury Secretary Henry Paulson’s plan to buy up toxic assets, to the universal astonishment of those present.

Only after Obama gave an overview of the Democrats’ approach and after other Republicans’ remarks — about 43 minutes into the meeting — did McCain finally acquiesce to taking the floor. Even then, the candidate didn’t say much at all, remarking that Republicans had “legitimate concerns” about the bailout and that the parties needed to “work together,” simply advancing platitudes.

So goes Jonathan Alter’s account in “The Promise: President Obama, Year One.” The financial crisis is just a single piece that the Newsweek senior editor addresses with respect to the Obama presidency; the book is a comprehensive overview. Yet, like the economic meltdown, much of the book has the effect of placing the reader in the moment, whether it’s Obama’s disciplined transition process — and readers will learn to what extent the president did measure the drapes before he was elected — to the long health care slog that only closed after a full year of partisan wrangling.

Alter attempts to detail all the important and compelling aspects of a nascent Obama presidency — juicy details notwithstanding. (Yes, Carla Bruni did ask Michelle Obama whether the first couple ever kept heads of state waiting while they were lovemaking.)

Alter aims to give a first-year retrospective and an explanation of what the president is like: “Never before have we known so little about someone so intensely observed,” he writes. Lastly, he assesses the commander in chief’s progress thus far.

It is a weighty undertaking, although much of the subject matter is still a work in progress. Alter bases his work on high-level interviews spanning mid-2008 to early 2010, White House records and occasional newspaper and magazine articles. His work offers mostly one-sided, albeit comprehensive, insight into a complex narrative. Indeed, he sees the book as contemporary history, offering a second draft to journalism’s first draft.

But despite the juicy vignettes from the 2008 campaign and the transition period — how exactly did Obama persuade Hillary Rodham Clinton to be secretary of State? — much of that time period is familiar territory to the politically astute.

Obama’s legendary cool, calm and collected demeanor comes to the fore when he is strategizing on legislation. Alter breaks little ground into the president’s psyche, and readers probably won’t come away from the book feeling as though they know Obama any better than before.

Nevertheless, the book is a reliable timeline to the headline issues of the past year, with everything from health care to the Afghanistan troop surge. Alter learns that Obama almost single-handedly pushed for continuing the reform effort in the face of many advisers’ objections, while the president is shown dressing down the military brass for perceived insubordination.

Dealings with the legislative branch offer many gems: At the outset, the president’s outreach to the Republican caucus on the stimulus legislation would come to no avail. Obama was more interested in speed and getting “points on the board,” while Republican incentives to compromise were lessened by the president offering tax cuts up front. The unanimous vote of Congressional Republicans against the American Recovery and Reinvestment Act “set the tenor for the whole year,” Obama said. “That helped create the tea-baggers and empowered the whole wing of the Republican Party to where it now controls the agenda for the Republicans.”

Coherent insight within the context of a reliable timeline is a rarity in the age of daily news bombardment. The fact that Alter is so readable, and that the book at times reads like a novel, is just icing on the cake. It’s a worthy refresher, especially when one keeps in mind that the account is largely one-sided and that the historical details have yet to be shaken out.