Complex sentence: After "buying" it (he hands the vendor a Japanese banknote and runs away before the vendor can do anything), he reads it and looks to the back to see that the writer and artist is Isaac Mendez.
Split into simpler sentences: After "buying" it (he hands the vendor a Japanese banknote and runs away before the vendor can do anything), he reads it. He looks to the back to see that the writer and artist is Isaac Mendez.