INTEGRAL response to the nova V5668 Sgr. Top three panels: measured counts rates of different instruments aboard INTEGRAL in 100 s time bins (blue data points). From top to bottom: IBIS/ISGRI, IBIS/Veto, and SPI-ACS. Bottom panel: count ratios between the Veto and the ACS (blue), and ISGRI and the ACS (orange) if a source at the position of V5668 exposed INTEGRAL with a nova-like spectrum. The blue and red data points mark the actually measured ratios during the 23 event times (vertical dashed green lines). See text for details.