  The solar corona is frequently disrupted by coronal mass ejections (CMEs),
whose core structure is believed to be a flux rope made of helical magnetic
field. This has become a "standard" picture although it remains elusive how the
flux rope forms and evolves toward eruption. While 1/3 of the ejecta passing
through spacecrafts demonstrate a flux-rope structure, the rest have complex
magnetic fields. Are they originating from a coherent flux rope, too? Here we
investigate the source region of a complex ejecta, focusing on a flare
precursor with definitive signatures of magnetic reconnection, i.e., nonthermal
electrons, flaring plasma, and bi-directional outflowing blobs. Aided by
nonlinear force-free field modeling, we conclude that the reconnection occurs
within a system of multiple braided flux ropes with different degree of
coherency. The observation signifies the importance of internal structure and
dynamics in understanding CMEs and in predicting their impacts on Earth.
