Little was away, so it was Education Minister Chris Hipkins who stood for the onslaught.
Reti delivered his left hook: could he confirm that annual health checks for seniors would be scrapped in the Budget, as the letter suggested?
Hipkins delivered one right back: the letter was a draft written up by Ministry of Health officials which Little had never sent. He suggested Reti wait the "one more sleep" until the Budget to learn more.
At this point, Reti should probably have guessed he was on a futile mission. He did not.
He ploughed on, asking about the proposal for 20 mobile dental clinics and a $200 million Pharmac boost in Budget 2021.
Again, Hipkins simply said the letter was a draft, and that Little did not agree with much of what was in it. It was never sent.
At this point, Reti should have had quite a fair inkling that he was on a futile mission.
He asked how the Government would explain reducing specialist services at provincial hospitals to rural communities.
Hipkins said the rural communities would take comfort from knowing the letter was not sent.
At this point, all of Reti's colleagues certainly knew he was on a futile mission: along the row from Reti, National MPs faces were a mix of sympathy, pained embarrassment and barely restrained amusement.
But Reti is not easily beaten down. He asked whether the Government was changing the eligibility for aged residential care and disability-related services as the letter proposed.
At this point the Acting Health Minister turned into the Education Minister and delivered a comprehension lesson to Reti.
"I think the biggest challenge we have here is a comprehension one. The letter was not the Minister of Health's letter. He did not write it, he did not agree with what was in it, and he did not send it."
At least two National MPs could not stop themselves laughing.
The same Question Time also delivered a mystery. National MP Nicola Willis was booted out of Parliament for the first time for calling out "oh, come on" after some pedantry from the Speaker.
But Parliament's microphones also picked up someone apparently uttering an obscenity at the same time.
Willis claimed it was not her – and was backed up by the Speaker. National MP Melissa Lee sits closer to the Speaker's microphone than Willis, but denied it was her, and the Speaker claimed he did not hear it at all.
The mystery remains unsolved.
As for Reti, the one question Reti should have asked but did not was the one that actually mattered: what was in the letter that Little did end up sending to Robertson?
The answer to that may well be revealed in the Budget on Thursday.
