Entry Plug

The Entry Plug (エントリープラグ, Entrī Puragu) was the cylindrical cockpit capsule inserted into an Evangelion unit’s spinal column, serving as the sole means by which a pilot could interface with the biomechanical giant. Filled with LCL fluid — a breathable oxygenated liquid — the Entry Plug created the physical and neural bridge between human consciousness and the EVA’s alien nervous system.

Design

The Entry Plug was a sealed cylindrical capsule approximately two metres in length, designed to be inserted into a recess along the Evangelion’s spine. Once locked into position, the plug established physical connections with the EVA’s neural pathways, enabling the synchronisation that allowed a pilot to control the massive machine.

The interior contained a single pilot seat surrounded by LCL fluid, instrumentation panels, and a harness system. Despite its cramped confines, the Entry Plug was the most critical component of the entire EVA system — without it, the Evangelion was merely a dormant husk.

LCL fluid

LCL (Link Connect Liquid) was the oxygenated fluid that filled the Entry Plug during operation. Smelling faintly of blood, LCL served multiple functions: it allowed the pilot to breathe whilst submerged, maintained the neural connection between pilot and EVA, and acted as a shock absorber during combat. The fluid’s composition was derived from the blood of the First Angel, Adam, making it a biological medium as much as a mechanical one.

When a pilot entered the Entry Plug, the LCL flooded the capsule, submerging them completely. The transition from breathing air to breathing fluid was disorienting for new pilots but essential for achieving the synchronisation ratio needed to operate the EVA.

Neural synchronisation

The Entry Plug’s primary function was to facilitate neural synchronisation — the process by which the pilot’s brainwaves were aligned with the Evangelion’s neural network. The synchronisation ratio determined how effectively the pilot could control the EVA; higher ratios meant more responsive and precise movement.

The children selected as pilots — Shinji Ikari, Rei Ayanami, Asuka Langley Soryu — possessed unusually high synchronisation potential, a quality that was not entirely coincidental given the Evangelions’ origins.

Safety and emergency systems

The Entry Plug was equipped with an ejection system that could explosively separate the capsule from the Evangelion in emergencies, allowing the pilot to escape if the unit was critically damaged. A self-destruct mechanism was also installed — a grim necessity given the potential consequences of an Evangelion falling into unauthorised hands or berserking uncontrollably.

Despite these safety measures, the Entry Plug was far from a safe environment. Pilots regularly sustained injuries during combat, and the psychological toll of the neural connection — experiencing the EVA’s pain and, in some cases, its memories — was considerable.

Significance

The Entry Plug represented the Evangelion franchise’s central tension between human and machine, self and other. The act of entering the plug — of submerging oneself in another being’s body and surrendering individual boundaries — was a physical metaphor for the series’ exploration of connection, vulnerability, and the pain of intimacy. The plug was both womb and prison, the only way to reach out to another and the site of profound psychological violation.

See also

• Evangelion units – The machines the Entry Plug controls
• NERV – Developer and primary operator
• S² Engine – The Angels’ power organ, related to LCL’s origins
• Evangelion portal
• About Evangelion

External links

• Entry Plug on the Evangelion Wiki