What did the Prime Minister know, and when did he know it? With the most memorable political scandals, it is the cover-up as much as the crime which tends to bring people down.
Rishi Sunak is adamant he was not told until the past few weeks that the problem of crumbling concrete in dozens of English schools was so bad it posed a serious danger to children and teachers.
However, veterans from the Department for Education are equally adamant that when chancellor, he did know how grave the risk was and nonetheless turned down the department’s funding request.
If Mr Sunak recklessly refused to commit the cash needed to keep children safe, that is bad. If he deliberately misled the public and Parliament, that is much worse.
There is not yet a smoking gun tying the Prime Minister directly to this crisis. But it could still prove damaging to his future political hopes – because it sums up the reservations that so many have about the Government.
After 13 years of Conservative rule, many feel the quality of the public realm has been steadily eroded, even as the tax burden has hit a record high. The Government continues to say that austerity was a necessity after the financial crisis; but rather than scale back the size of the state, it merely starved existing services of funding, forcing them all to run at a lower level than before.
The political headaches keep coming: the escape of a suspected terrorist from prison, dressed as a chef and clinging to a van, is hugely embarrassing for the Government too. But it is voters’ concerns about their everyday life that explain why the Tories are doing so poorly in the polls, and why Mr Sunak’s turnaround job is such a big one.