The cover image, by S. R. Shah et al., is based on the Original Article Sofosbuvir plus ribavirin in treatment‐naïve patients with chronic hepatitis C virus genotype 1 or 3 infection in India, DOI .

The evolution of the spectral energy distribution during flares constrains models of particle acceleration in blazar jets. The archetypical blazar BL Lac provided a unique opportunity to study spectral variations during an extended strong flaring episode from 2020-2021. During its brightest 𝛾-ray state, the observed flux (0.1-300 GeV) reached up to 2.15 × 10 −5 ph cm −2 s −1 , with sub-hour scale variability. The synchrotron hump extended into the X-ray regime showing a minute-scale flare with an associated peak shift of inverse-Compton hump in gamma-rays. In shock acceleration models, a high Doppler factor value >100 is required to explain the observed rapid variability, change of state, and 𝛾-ray peak shift. Assuming particle acceleration in mini-jets produced by magnetic reconnection during flares, on the other hand, alleviates the constraint on required bulk Doppler factor. In such jet-in-jet models, observed spectral shift to higher energies (towards TeV regime) and simultaneous rapid variability arises from the accidental alignment of a magnetic plasmoid with the direction of the line of sight. We infer a magnetic field of ∼ 0.6 G in a reconnection region located at the edge of BLR (∼ 0.02 pc). The scenario is further supported by log-normal flux distribution arising from merging of plasmoids in reconnection region.