Top panel: Fermi-LAT light-curve of 3C 454.3 from 2013 to 2014 August, including the 2013 September 23–25 flare, the 2013 October 5–2014 May 20 pre-flare (phase 1), and the 2014 May–July outburst (phases 2, 3, 4), with 1 day binning. Gaps appeared in the light-curve during the pre-flare due to low-exposure modes. Middle panel: photon index (Γ) vs. time. Bottom panel: arrival time and energy of E > 10 GeV photons with three different significance levels of source association (2-, 3-, and 4-σ Gaussian equivalent). Vertical dashed lines separate the four phases studied.