The Whitechapel Fiend

Jack the Ripper stalks through London, and only the Shadowhunters can stop him. One of 10 adventures in Tales from the Shadowhunter Academy.
Simon learns the truth behind the Jack the Ripper murders — “Jack” was stopped by Will Herondale and his institute of Victorian Shadowhunters.
This standalone short story follows the adventures of Simon Lewis, star of the number-one New York Times best-selling series The Mortal Instruments, as he trains to become a Shadowhunter. Tales from the Shadowhunter Academy features characters from Cassandra Clare's Mortal Instruments, Infernal Devices, and the upcoming Dark Artifices and Last Hours series. The Whitechapel Fiend is written by Cassandra Clare and Maureen Johnson.