Despite the remarkable progress made in the coordination chemistry and photophysics of Fe-carbene complexes, consistent mechanistic understanding of the undergoing excited-state dynamics is often still lacking; this profound knowledge could in fact also be the key for real-life applications for solar cells and photocatalysts. Inconsistencies may typically be rooted in discrepancies in interpretations, stemming from the complexity of data acquired by time-resolved (pump-probe) experiments and/or approximations made in theoretical models for excited-state simulations. For Fe-NHCs, the scenario is best illustrated by the case of the very first discovered Fe-NHC photosensitiser, [Fe(bmip) 2 ] 2+ (bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)-pyridine), shown in Figure , right. Utilising transient optical absorption spectroscopy (TOAS) with 485 nm pump, Liu et al. identified two timescales, <100 fs and 9 ps, which they attributed to 1 MLCT → 3 MLCT intersystem crossing (ISC) and 3 MLCT → 3 MC decay, respectively, see Figure . Our quantum wavepacket dynamics simulations in highlyreduced nuclear configurational space (4D 17 and 5D ) supported this assignment, identifying a ∼100 fs 1 MLCT → 3 MLCT ISC process, and the 3 MLCT → 3 MC transition occurring on ps timescales (with time constants of ∼1 ps and ∼4 ps). More recently, utilising fs-resolved X-ray emission spectroscopy (XES) Kunnus et al. identified that upon 400 nm excitation, the 3 MLCT decay exhibits branching with a ∼110 fs 3 MLCT → 3 MC component (40%) and a ∼9 ps one (60%), the latter being identical to the 3 MLCT lifetime determined by TOAS; we note that a similar branching was observed for a COOH-derivative of [Fe(bmip) 2 ] 2+ by vibrational coherence spectroscopy . Furthermore, coherent oscillations with a 278 fs period were identified in the time-resolved XES and X-ray solution scattering (XSS) signals, assigned to breathing wavepacket motion in the 3 MC state; such oscillations are also apparent in the TOAS data but were not analysed and in most cases were not observed by XES. Clearly, there is a significant difference in these experimental assignments, i.e., TOAS (485 nm excitation) vs XES (400 nm excitation), as well as the XES data vs theory in the appearance of the ∼100 fs 3 MC component. This ultrafast MLCT quenching channel could in fact have a vital role as it challenges the general picture of Fe-carbenes possessing long-lived MLCT states and potentially weakens the complex's photosensing ability. Crucially, using full-dimensional hybrid quantum-classical excited-state simulations, we herein clarify and explain all important aspects and ambiguities of [Fe(bmip) 2 ] 2+ , fully resolving its excited-state dynamics.