Single cell genomics approaches are revolutionising how immunology is studied. However, in the absence of a time machine, one cannot both ascertain the molecular profile of a single cell AND its clonal destiny. This is because measurement of one (e.g. destructive single cell RNA-seq) precludes testing of the other (e.g. clonal fate). Instead, we have developed clonal multi-omics that solves the time machine dilemma. Here, daughters of individual clones are tested separately for gene expression and fate, thus identifying the regulators of clonal behaviour. We have also developed novel clonal lineage tracing tools, including a novel LoxCode mouse that performs in situ barcoding to unravel the complexity of haematopoiesis. This talk will highlight how we are using these approaches to tackle questions in dendritic cell development and haematopoiesis, more broadly.