Imani, adopt­ed as an infant, is about to become a bat mitz­vah. As she thinks about what this rite of pas­sage means to her, Imani also won­ders about her birth par­ents and who they are. She has been raised by a warm, sup­port­ive, and lov­ing Jew­ish fam­i­ly, sur­round­ed by par­ents and a broth­er who adore her, an extend­ed fam­i­ly she cher­ish­es, an active cir­cle of friends, and teach­ers who would be the envy of many. But as a young, black, soon-to-be-woman in a sea of most­ly white faces, she can’t help won­der­ing about her birth parents.

Imani’s Hebrew school class, as part of prepa­ra­tion for the bar/​bat mitz­vah year, plunges into a spe­cial project that involves geneal­o­gy and explo­ration of fam­i­ly roots. Dur­ing this same peri­od of time, Imani’s beloved grand­moth­er, Anna, dies and the diary she wrote as a child is dis­cov­ered in her apart­ment, tucked away on a crowd­ed book­shelf. Anna has promised the books to Imani and now the diary belongs to her, as well.

As she pre­pares for her bat mitz­vah, Imani fol­lows Anna’s sto­ry through the pages of her diary. Anna, born in Lux­em­bourg, was sent to the Unit­ed States as a child, right before the Holo­caust. Her par­ents and sib­lings, includ­ing an iden­ti­cal twin sis­ter, had hopes of fol­low­ing as soon as pos­si­ble, but the tim­ing was not in their favor; they per­ished in a con­cen­tra­tion camp. Read­ing her grandmother’s sto­ry, Imani thinks about search­ing for her bio­log­i­cal family’s roots, and the impact that might have on her adop­tive fam­i­ly and her future.

This is a year of tremen­dous growth for Imani, as a pre-bat mitz­vah year should be; the read­er watch­es as she deep­ens her under­stand­ing of who she is and of the world around her — page by page, emo­tion by emo­tion. The nar­ra­tive flips back and forth between Anna’s voice and Imani’s, result­ing in a tex­tured expe­ri­ence for the read­er. The string men­tioned in the book title refers to a unit of mea­sure­ment, but also sug­gests con­nec­tions between past and present, across an ocean, and onward into the future.

This is an excel­lent book for mid­dle grade read­ers and above who are inter­est­ed in learn­ing about the Holo­caust but are not yet pre­pared to plunge too deeply into the hor­rors of the peri­od. It presents the his­to­ry of a ter­ri­ble time but includes pos­i­tive ele­ments and hope­ful moments.