Avi­va vs. the Dyb­buk is a sto­ry of a girl who has lost her father and is try­ing to make peace with how her life has changed since that day. When Aviva’s father, the shamash who man­aged the local Ortho­dox syn­a­gogue, dies, Aviva’s moth­er becomes so upset that she refus­es to leave the house. Their home is the local com­mu­ni­ty mik­vah, which also seems to house a dyb­buk who only Avi­va can see, caus­ing trou­ble for Avi­va and her moth­er. A dyb­buk is, in Jew­ish folk­lore, a wan­der­ing soul. Through­out the sto­ry, Avi­va attempts to find ways to free her­self of the dybbuk.

Avi­va has also lost her close friend­ships and feels very much alone. Due to an unfor­tu­nate inci­dent, Avi­va must plan a school event, at the insis­tence of her school’s admin­is­tra­tion, with her for­mer best friend and cur­rent neme­sis. Through their work togeth­er, the rev­e­la­tions shared as they work on the project, and the unex­pect­ed sur­pris­es they come across, they redis­cov­er their friendship.

Aviva’s fam­i­ly and com­mu­ni­ty are all Ortho­dox Jews. Many Hebrew or Yid­dish terms are used through­out the book, and there is a glos­sary at the back that explains what they mean. Along with the strong theme of friend­ship, which is heav­i­ly empha­sized, there are also anti­se­mit­ic inci­dents that occur. The mys­ter­ies sur­round­ing Aviva’s father’s death and her mother’s extreme fears grad­u­al­ly become clear.

The book ends on a pos­i­tive note, show­ing how a whole com­mu­ni­ty, both Jews and non-Jews, can work togeth­er to make things bet­ter. In the process, Avi­va gains friends and peace.