During their first public outing together, Meghan Markle and Prince Harry knew something the rest of the world didn't.

According to the new book "Finding Freedom: Harry and Meghan and the Making of a Modern Royal Family," when the pair made their first public appearance together at the 2017 Toronto Invictus Games, they were already engaged to be married, People magazine reports.

Markle and Harry, now 38 and 35 respectively, met in 2016 on a blind date.

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During their big day out, Markle even dropped a very subtle hint that Harry was already her groom-to-be.

Meghan Markle (left) and Prince Harry at the 2017 Toronto Invictus Games. They were reportedly secretly engaged at the time, according to a new book. (Photo by Chris Jackson/Getty Images for the Invictus Games Foundation )

Meghan Markle (left) and Prince Harry at the 2017 Toronto Invictus Games. They were reportedly secretly engaged at the time, according to a new book. (Photo by Chris Jackson/Getty Images for the Invictus Games Foundation )

She donned a simple white, button-down shirt -- a style often referred to as a "husband shirt," per People.

In November, the couple revealed their engagement but were somewhat coy about the exact date that Harry popped the question.

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"It happened a few weeks ago, earlier this month, here at our cottage; just a standard typical night for us," said Harry, per the outlet, in an interview regarding his then-upcoming nuptial.

Prince Harry and Meghan Markle. 

Prince Harry and Meghan Markle.  (Karwai Tang/WireImage via Getty)

"It just – just [was] an amazing surprise, it was so sweet and natural and very romantic," added Markle. "He got on one knee."

"Finding Freedom" chronicles the life of the Duke and Duchess of Sussex, examining everything from the beginning of their romance to their historic "Megxit" announcement.

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In a statement previously obtained by the outlet, a spokesperson for Markle and Harry said the two "were not interviewed and did not contribute to 'Finding Freedom.'"