In Chap­ter IV, Miss Rose­mary hints at a birth­day cel­e­bra­tion for Mibs, cre­at­ing a tense atmos­phere at the table as the Beau­mont fam­i­ly grap­ples with their fam­i­ly tra­di­tions sur­round­ing birth­days. While oth­ers seem to expect joy, Fish, Mibs’ broth­er, is vis­i­bly strained by the talk of a par­ty, indica­tive of the fam­i­ly’s unspo­ken under­stand­ing that thir­teenth birth­days are typ­i­cal­ly pri­vate affairs. Gyp­sy, being just three years old, is bliss­ful­ly unaware, express­ing excite­ment for bal­loons and icing.

Despite Mibs’ reluc­tance and truth­ful­ly stat­ing she lacks friends, Miss Rose­mary insists on orga­niz­ing a par­ty for her, using cheer­ful deter­mi­na­tion. Mean­while, Mibs’ sis­ter Bob­bi is dis­mis­sive and mocks their moth­er, reveal­ing the fam­i­ly’s fric­tion as she empha­sizes her dis­dain for the planned cel­e­bra­tion. The con­ver­sa­tion con­tin­ues as Miss Rose­mary attempts to con­vince Mibs to invite class­mates, but Mibs inward­ly wish­es to avoid the pub­lic atten­tion sur­round­ing her birth­day.

Reflect­ing on past cel­e­bra­tions, Mibs recalls a vivid mem­o­ry of Rock­et’s thir­teenth birth­day, where their Grand­ma Dol­lop engaged them in can­ning radio waves—a whim­si­cal task that includ­ed cap­tur­ing sounds of songs and sto­ries from the air. The day had been charged with an atmos­phere of wor­ry for Rock­et, who feared inher­it­ing an ordi­nary fate with­out spe­cial abil­i­ties, unlike his sib­lings who had shown promise. The mem­o­ry cul­mi­nates in a dra­mat­ic moment where Rock­et dis­cov­ers his own spe­cial tal­ent, pro­duc­ing chaos and spec­tac­u­lar radio sounds dur­ing a pow­er out­age, mark­ing him as unique with­in the fam­i­ly.

As Mibs pre­pares for her own sig­nif­i­cant birth­day, she does not wish for extra­or­di­nary tal­ents but instead fer­vent­ly prays for soli­tude, hop­ing that no one will attend her par­ty. This sets the stage for the emo­tion­al land­scape of the chap­ter, high­light­ing the con­flict between fam­i­ly expec­ta­tions and indi­vid­ual desires, encap­su­lat­ing Mibs’ grow­ing anx­i­ety and desire for peace amidst fam­i­ly pres­sures.