Pediatric hematopoietic stem cell transplant (HSCT) is an intensive treatment that can be life-threatening. All family members experience distress. We conducted a grounded theory study using a family systems-expressive arts framework to develop a theoretical understanding of the family experience of HSCT. Six families (15 family members) participated in two interviews, drew an image, and were guided through a “dialoguing with images” process. Participants did not always perceive HSCT as an experience they had lived as a family and were surprised to hear other family members’ experiences. While one mother drew, she suddenly understood it was not only her ill child, but the entire family who had “fallen down the rabbit hole.” The family experience of HSCT is described across (a) the pre-HSCT trajectory, (b) family fragmentation (hospitalization), and (c) family reintegration. We identified a critical need for targeted family intervention during the transition into HSCT, throughout and following hospitalization.