Final answer:
The phrase indicates that someone intended to share a secret or private information with Ona soon.
Step-by-step explanation:
The phrase "to be confided in" means to be told something in a private or personal way, often something that is significant or confidential.
The adverb "before long" indicates that this revelation would happen soon, implying that the matter was urgent or important enough to be shared promptly.
The sentence leaves the nature of the secret or information undisclosed, creating a sense of anticipation or intrigue. It suggests that Ona is a trusted individual who is worthy of being entrusted with such sensitive information.
The use of the passive voice ("was to be confided") emphasizes the inevitability of this revelation, hinting that Ona's role in the matter is crucial.
So, the sentence "Ona was to be confided before long..." suggests that Ona was soon to be entrusted with a secret or important information.