Answer:
Paul Revere’s friend will send a secret signal to inform him of the British army’s plan.
Step-by-step explanation:
In the poem "Paul Revere's Ride" the main character is Paul Revere. The story begins in Boston, where he converse with his friend about the British army and how to accomplish his plan of warning people about the army when he still doesn't know will the army march on land or go in boats. So in the given stanza we have Paul Revere’s instructions to his friend who should hang one lantern in the church belfry if they go marching on land, or two lanterns if they take the sea road.
So it turns out that they will go by sea, the friend hangs two lanterns, Paul Revere sees that and he spends the night riding through the countryside warning people about the upcoming army.