In the 1960s, the head of a NYC Child Devel­op­ment Cen­ter and a psy­chi­a­trist from Colum­bia Uni­ver­si­ty tracked the devel­op­ment of twins and triplets relin­quished for adop­tion and delib­er­ate­ly giv­en to dif­fer­ent fam­i­lies. The adop­tive par­ents were nev­er told they were rais­ing one twin — the inves­ti­ga­tors insist­ed that the sep­a­ra­tion be kept secret. Segal reveals the inside sto­ries of the agency that sep­a­rat­ed the twins, and the psy­chi­a­trists who observed them. This study was hard­ly known until the release of two recent films, Three Iden­ti­cal Strangers and The Twin­ning Reac­tion, that left view­ers shocked, angered, sad­dened, and want­i­ng to know more. Through records, let­ters, and inter­views with the col­leagues, friends, and fam­i­ly mem­bers of the agency’s con­sul­tant and study’s inves­ti­ga­tors, as well as jour­nal­ists, ethi­cists, attor­neys, and — most impor­tant­ly — the twins and their fam­i­lies, Segal tells dis­turb­ing truth about the study. The spell­bind­ing sto­ries of the twins’ sep­a­ra­tion, loss, and reunion offer read­ers details that, until now, have been lost to the archives of history.