Hybrid vigor, a key example of system-level emergence, already intrigued Darwin. Whether it constitutes a single phenomenon or rather a collection of syndromes, and whether hybrids are equipped to bypass classical life-history trade-offs, remain unclear. Taking a systematic approach, I study the genetic, transcriptomic, and phenotypic covariance in a large number of Arabidopsis thaliana F1 hybrids, and strive to understand how genetic variants combine in the F1s, the mode of gene expression, the associated pathways, as well as the potential cost to the apparent growth vigor.