Meeting Mr Wainscott

"𝒴𝑜𝓊'𝓇𝑒 𝓈𝑜 𝒜𝓇𝓉 𝒟𝑒𝒸𝑜.
𝒮𝒽𝒾𝓃𝒾𝓃𝑔 𝓁𝒾𝓀𝑒 𝑔𝓊𝓃𝓂𝑒𝓉𝒶𝓁, 𝒸𝑜𝓁𝒹 𝒶𝓃𝒹 𝓊𝓃𝓈𝓊𝓇𝑒."

Anxious and scared, ex-surgeon and renowned astrophysicist Friday Barnes fears for her only child when she places him in a new kindergarten.
Ex-Pro Boxer, now a kindergarten teacher, makes her feel better about it.
So why does he look so familiar? Why does he have all of these scars on him?
And, most importantly, why does she get the feeling they've met before?