David M. Booher 
All-New Firefly #4 [PDF ebook] 

The crew of the Serenity have some emotional exchanges while they ruminate on missing Shepherd Book, and regret how helpful he could have been with the Monastery, especially with the Monks mourning one of their own. After Mal leaves the monks with the means to defend themselves, a man with a crutch and a respirator shows up with a boy, revealing a shocking connection to Jayne!