Spotty wrasses (Notolabrus celidotus) undergo socially cued female-to-male sex change as adults. We combine captive social manipulations and time-series sampling with transcriptomic and methylome approaches to describe the molecular cascade that orchestrates gonadal metamorphosis. Our findings reveal at a molecular level how a normally committed developmental process remains plastic and is reversed to completely alter organ structures. Overall design: Captive social groups of wild-caught spotty wrasses from the Tauranga region in New Zealand were established and females induced to change sex using chemical (aromatase inhibitor fadrozole) or social (removal of dominant male) manipulations in 2014-2018. Time-series sampling was used to obtain biological replicates of transitional animals at early, mid and late stages of sex change. Females from unmanipulated tanks, plus the original males served as controls. Gonadal tissue was collected from each animal for genomic and histological analyses. RNA sequencing libraries were prepared for 95 total samples using Illumina’s tru-seq stranded mRNA kit and sequenced using 2x125bp paired end Illumina HiSeq 2500. Cleaned reads were mapped to the N. celidotus genome using Rsubread and read counts were generated using FeatureCounts.