Thanks to the botched summoning, Shirou and Saber's connection isn't quite functioning properly. It seems she'll need to replenish her mana in some other manner. Despite being an eroge, Fate/stay night isn't exactly known for having great sex scenes; this is my attempt at making those in the Fate route at least marginally better.
It is said that for Shirou and Saber to reunite, two miracles must occur: "one must wait continuously, one must pursue endlessly." What happens when one person decides to take on both roles?