[How about the water flooding the surrounding areas and some helpful magic makes this retelling quicker?
For a moment, it's like they're back at that area outside Paris, Grimaud holding Aramis as he tries to escape, Porthos catching up to them, clearly injured. Aramis is used as a shield, a role he takes most enthusiastically, but of couse this Porthos in the memory doesn't shoot.
The place returns to normal just as Grimaud manages to finally escape, at least leaving Aramis behind alive.]