Final answer:
The quote in question is from Shakespeare's 'Macbeth', and it reveals the protagonist's contemplation of murdering Banquo, his friend. The lines examine the relationship between Macbeth and Banquo and highlight themes such as ambition, the supernatural, and fate.
Step-by-step explanation:
The quote 'It is concluded, Banquo, thy soul's flight, if it find heaven, must find it out tonight' comes from Shakespeare's play Macbeth. This line is said by Macbeth, contemplating the murder of his friend Banquo. The various extracts presented from the play showcase the evolving relationship and suspicions between Macbeth and Banquo, especially after the prophecy by the three weird sisters.
Banquo's character acts as a foil to Macbeth, displaying nobility as opposed to Macbeth's ambitious demeanor. Banquo remains suspicious of Macbeth’s rise to power and his dialogue reflects a thoughtful and cautious character. The referenced lines include Banquo’s observations about the nature of the place where King Duncan is staying, his reflections on the supernatural, and ultimately his understanding that Macbeth’s kingship might not have been a stroke of mere luck.
This culminates in the awareness that Macbeth’s ambition may lead to Banquo's own downfall, hence Macbeth’s words about Banquo’s soul finding heaven refer to the planned assassination of Banquo, which Macbeth believes will secure his own power.