Shall I not, then, be stifled in the vault,
To whose foul mouth no healthsome air breathes in,
And there die strangled ere my Romeo comes?
– William Shakespeare
Romeo and Juliet, Act 4, Scene 3. Juliet is thinking about the things that can go wrong if she takes the sleeping potion to give her the appearance of death. She is terrified of wakening up early in the family burial vault before Romeo arrives and suffocating.