FACTS is a Wales-wide mental health service for 10-17-year-olds with needs beyond the remit of mainstream child and adolescent mental health services (CAMHS). As a purely consultation-liaison service, it differs from other UK services in the field. To describe a complete cohort of referrals to FACTS 2013-2017 with service exit by June 2018. Clinical, social and offending data were extracted from FACTS records. 80 young people completed a FACTS episode, averaging nearly a year (309days; range 13-859days). Mostly boys (65, 81%) of mean age 15.4years (range 9-18), two-thirds (n=53) had three or more referral reasons, one invariably being threatened/actual harm to others; only half were criminal-justice involved. Half (41, 51%) were committing sexually harmful acts. Half were self-harming (41, 51%). All but seven had had at least one adverse childhood experience (ACE), nearly half (35, 44%) four or more. Nevertheless, post-traumatic stress disorder (PTSD) was rarely diagnosed (7, 9%); just over one-quarter (23, 29%) had no diagnosis at all. Correspondence analyses endorsed two distinct Attention deficit hyperactivity disorder groups, distinguished by presence/absence of evidenced brain damage or dysfunction. Suicide-related behaviours clustered with the other diagnoses, flashbacks and psychotic symptoms with no diagnosis. Change in home circumstances during a FACTS episode was slight. The complexity of presenting problems and service involvement evidences need for FACTS. The extent of persistently harmful sexual behaviours is a novel finding, suggesting need for more expert input for this at other service levels. Rarity of PTSD diagnoses was surprising given the extent of ACEs. This raises concerns that services focus on disorder signs rather than the child's inner life. Given the extent of problems, minimal change may be a positive outcome - especially when remaining in the community. Further development of this service should include explicit case-by-case goals and indicative outcome markers.