Otherwise known as:
“An Examination of Collegial Dynamics as Expressed Through Marksmanship, or, LADIES’ DAY OUT: A Cas Russell Short Story”
Cas teaches Pilar to shoot. Considering Cas is an acerbic mercenary and Pilar is a delightful admin, this goes about how you’d expect.
This 8,000-word short story is a companion to the Cas Russell series and takes place between book 2 (Half Life) and book 3 (Root of Unity). The best time in the series to read it is between books 2 and 3 or directly following book 3.
This story is also available for free online.