Answer: Because in the letter Friar Laurence explained the plan and stated that Juliet was only apparently dead.
Explanation: In Act V, Scene II of "Romeo and Juliet" by William Shakespeare, Friar Laurence is in a panic when he finds out that his letter was not delivered to Romeo because in the letter he explained him the plan and stated that Juliet was only apparently dead. Friar Laurence is afraid that Juliet wakes up alone in the graveyard, and that Romeo knows nothing of the potion he gave Juliet.