By Tom Bateman
BBC Middle East Correspondent
Early in the morning, as Russia's isolation grew, a jet took off from Tel Aviv bound for Moscow. It happened in secret, carrying a VIP delegation. The plane touched down with a reverse thrust: a hot blast into Moscow's dawn while Russia was being frozen out by the West.
This was last Saturday - incidentally the Jewish Sabbath, when tradition says the rest day can be broken to save a life. Onboard were at least two observant Jews working when they normally wouldn't - Israeli Prime Minister Naftali Bennett and Housing Minister Zeev Elkin, plus four officials. Mr Elkin was there, it was said, to help with the translation. He's a native Russian speaker, born and brought up in Kharkiv, the Ukrainian city under relentless Russian bombardment. He has close relatives there; now he was going to meet the war's architect.
The Israelis headed to the Kremlin. Mr Bennett was the first foreign leader to speak to Vladimir Putin in person in response to the invasion of Ukraine. We don't know much about the meeting, whether they were sat six metres (20ft) apart across that glossy white table (the treatment European leaders got in the run up to war). None of the substance leaked at the time. There was nothing to see and little to hear. An invisible liaison.
But the meeting itself was the story. Could Israel be the unlikely broker in the worst crisis between Russia and the West since the Cold War?
News of the meeting was released as it reached its third hour, making global headlines.
Israel has significant relations with both Russia and Ukraine, and Mr Bennett had been trying to position himself as a go-between.
There are some immediate concerns for the Israelis. There are at least a quarter of a million Jews in Ukraine, eligible to make Israel their home under its "Law of Return".
But Mr Bennett was flying into something he sees as strategic in the crisis.
Israel has also developed frequent dialogue with the Russians, or "our neighbours to the north" as one official reportedly referred to them recently. Russia controls the skies over Syria, where Israel routinely carries out air strikes. It says it targets weapons transfers and militants linked to Iran, the country it sees as an existential threat.
Now the relationship dynamics of one regional crisis are becoming entangled in another.
Israel's leadership believes its Russia links are an opening. One Israeli official put it to me that it can be a "bridge" between Moscow and the West. Prime Minister Bennett even called it a moral obligation to make every effort to extend dialogue.
There have been three rounds of direct talks between Ukrainian and Russian officials in Belarus. The first attempts at local ceasefires to allow so-called humanitarian corridors barely held, under disputed circumstances.
Any terms of a more permanent truce go the roots of the crisis. Russia demands that Ukraine declares itself "neutral", permanently renounces future Nato membership, and gives up chunks of territory. Ukrainian President Volodymyr Zelensky promises to fight on. He says he is ready for dialogue, but "not for capitulation".
It's unlikely Israel can play mediator in the usual sense of a powerful arbiter that tries to entice each party into concessions. It would have to be more of a message carrier, shuttling between unequal sides. Some question the value of such an attempt.
Israel's leadership has decided largely not to fall in with the West's approach to Russia. It has not, for example, joined much of the barrage of fresh sanctions against Moscow.
This is a gamble on helping create an environment of de-escalation, but it's high risk.
It has sparked a fiery debate within Israel. First, when it didn't sign up to a text condemning Russia at the UN Security Council. Some called this a serious mistake - alienating the US, Israel's long-time ally. There was some direct criticism of Russia, but it was left to the Foreign Minister, Yair Lapid. Israel did eventually join the vote to condemn Moscow at the UN General Assembly.
Israeli officials are at pains to say the Kremlin meeting had the blessing of the US. But one veteran Israeli journalist quoted American officials as being sceptical about Mr Bennett's moves, thinking it unlikely that he could change Mr Putin's mind. Since then, more reported details of their calls have emerged, with Israeli officials quoted as suggesting Russian and Ukrainian positions in talks may be "softening". It was the first significant piece of news about any kind of broader agreement and is likely to give energy to Israel's efforts.
However, other commentators caution that only a fool could trust Vladimir Putin now.
Israel is prepared to be a go-between. It believes it's a card that should be kept on the table, which the West can play if it needs. Of course, it's not the only lens in the Middle East through which the war is seen.
Many in Arab countries, having lived the aftershocks of American and British invasions, condemn the West for what they see as its double standards over Ukraine. Palestinians point to Western backing for Ukrainian resistance and celebration of its leaders and ask: What about us? Israeli critics of this argument have been very vocal too, saying there is no equivalence between the two conflicts.
Meanwhile Turkey, historically a bridge between East and West, is also in the fray for dialogue between Russia and Ukraine. It's hosting their foreign ministers in the Mediterranean city of Antalya.
As for Mr Zelensky, he has welcomed Israel's potential mediation, but revealed frustration too. The Ukrainian president was asked whether, as a Jewish man, he had expectations of the Jewish state? "Our relations are not bad, not bad at all," he said. But he added, referring to Mr Bennett: "I don't think he is wrapped in our flag."
Perhaps that's what's needed from a potential mediator. Mr Zelensky has thanked the Israeli leader for attempts to "end the war". But that still feels a dim prospect despite Saturday's diplomatic flurry. Since then, the calls have continued, but the roar of the jet to Moscow has fallen silent.