The shadows stretching across the Middle East and beyond, since the start of the Israel-Gaza war, are now longer and darker with the killing of senior Hamas leader Saleh al-Arouri in Lebanon.
Arouri, a deputy political leader of Hamas, was killed in a drone strike in southern Beirut. He was a key figure in the Izzedine al-Qassam Brigades, Hamas's armed wing, and a close ally of Ismail Haniyeh, the Hamas leader. He had been in Lebanon acting as a connection between his group and Hezbollah.
Even before the 7 October war erupted, Lebanese Hezbollah leader Hassan Nasrallah had warned that any targeted attack on Lebanese soil would trigger a "powerful response".
But Hezbollah and its Iranian allies know the shape of their reply now, in the burning heat of hostilities, could change the shape of this war - and Hezbollah's fortunes.