A surprise re-flowering of the clematis montana

From my regular perch by the back door I noticed this hoverfly attracted to the second flowering of the clematis montana in the nearby hedge. I don't think I've seen them re-flower in the late summer, as normally they are one of the first flowering plants in springtime. The hoverfly seemed happy, and probably wouldn't have come across it before as it may not have been alive or feeding in springtime. Luckily with a slight adjustment my view wasn't obstructed by the trellis.