You should not inject a needle into your veins.
Hank is training to be a nurse in school and is practicing how to give injections, with volunteers nearby.
Hank wants to inject a person.
Hank gets a volunteer and inserts a needle into him.
Hank inserts the needle into his own vein, not wanting to bother a volunteer.
The volunteer flinches, but Hank keeps his hands steady and succeeds.
Hank flinches while inserting the needle and twists it, causing blood to spurt out of him.