Quote:"Why are you panicking?"
"Emiya Kiritsugu just checked in to the Osaka Continental."
Shortly before the Fourth Holy Grail War, with some temporal fudge-factor assigned to make the timelines line up, Emiya Kiritsugu and his party are waiting for their residence near Fuyuki to be ready. Taking advantage of the promised neutrality ("No business may be conducted on Continental grounds"), they've checked in to the Osaka Continental to enjoy the wait.
In comes Kerry's old 'friend', John Wick.
And a lot of people who say the High Table wants John and anyone even remotely associated with him dead.
To Artoria Pendragon, the situation is simple: She's a guest, her host is under attack, she is obligated to come to their defense.
The High Table are aware of Emiya Kiritsugu and the Moonlight World in general. They have dealt with mages before.
They were not prepared for Heroic Spirit level shenanigans.