© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. The Back Cover shows a depiction of the carbon cycle for a tunable set of chemistry that can be used to synthesize exceptional jet fuel via n-alkyl methyl ketones. In this work, methyl ketones, which can be derived from biomass in either chemical or hybrid biological-chemical pathways, are selectively transformed to cyclic trimers by aldol condensation and Michael addition. By altering the ratio of starting methyl ketones, an alkane blend can be generated after hydrodeoxygenation that not only satisfies the low freezing point necessary for jet fuel, but also the broad volatility distribution typical of petroleum-derived fuels. The carbon generated by combustion of these fuels then produces further biomass, completing the carbon cycle. More details can be found in the Full Paper by Sacia etal. (DOI: 10.1002/cssc.201500002).