Final answer:
Frederick Douglass's foiled escape plan led to his writings and international involvement, which substantially bolstered the abolitionist movement and his role as an activist.
Step-by-step explanation:
How the foiled escape plan ended up working in Frederick Douglass's favor is a significant aspect of his life's narrative and his role in the abolitionist movement. After his successful escape from slavery, Douglass published his autobiography, 'Narrative of the Life of Frederick Douglass, An American Slave Written by Himself', in which he detailed his experiences as a slave and identified those who had mistreated him. This bold move caused him to flee the United States due to the threat of murder, but it also led to his international travels to Great Britain, where he gained considerable moral and financial support for the anti-slavery cause.
Consequently, Douglass's narrative, his experience, and his work in the abolitionist movement gained substantial recognition, contributing to the pressure put on the United States to abolish slavery. His foiled escape plan ultimately allowed him to speak more freely and authoritatively against the horrors of slavery, thus working in his favor by amplifying his impact as an activist in the cause for freedom and human rights.