Snape thinks that Voldemort intends for him to complete the task in the end, but is determined that Draco ought to consider 1st, as Draco's achievement would make it possible for Snape to carry on in his part being a spy at Hogwarts for for a longer period. ” Or, https://kylervadhl.oneworldwiki.com/5171995/new_step_by_step_map_for_harry_potter_and_the_deadly_hallows