This is a list of events that occurred in 2257:
- Jason Ironheart begins a secret project for the Psi Corps. 
- John Sheridan learns the name of Bureau 13 before his informant dies. 
- EAS Agamemnon goes onto the Rim. 
- The Drazi Freehold adds missile launchers to the standard armaments of the Sun-Hawks.
- Commercial telepath Lyta Alexander concludes her assignment to Xenocorp and departs Earth for Babylon 5 aboard United Spaceways transport Delta Gamma 9. 
- Carolyn Sykes stops off in the Damocles Sector aboard her trade vessel, the Ulysses on her way to Babylon 5. 
- The IPX ship Icarus lands on Alpha-Omega III. The event is recorded by Vorlon probes left to monitor the area and the information is relayed to Kosh aboard his ship while en route to Babylon 5.
- Del Varner, a 'tech-runner,' arrives in the Tigris Sector to sell a Changeling net to a member of the Minbari Wind Swords clan. Thinking he missed his contact, he continues on to Babylon 5, not realising the Minbari is secretly following him. 
- Lyta Alexander arrives on Babylon 5. 
- The Minbari assassin secretly boards Babylon 5 using a one person Breaching pod. He later kills Del Varner and uses the changeling net to impersonate him.
- Carolyn Sykes arrives on Babylon 5 aboard her trade vessel, the Ulysses, twenty minutes before Ambassador Kosh's ship docks.
- Ambassador Kosh's ship arrives at the Epsilon III Jumpgate two days ahead of schedule. Upon leaving his ship the Minbari assassin approaches Kosh in the guise of Jeffrey Sinclair, whom Kosh recognises as Entil'Zha Valen. When he extends a hand in greeting to his 'old friend' the Minbari slaps a skin tab dosed with Florazyne, causing Kosh to collapse and lose consciousness. 
- Against the wishes of the Vorlon Empire, Doctor Benjamin Kyle opens Kosh's Encounter suit and determines that Kosh has indeed been poisoned and with the rate that his life signs are dropping, will die within the next 24 hours.
- With the confirmation of an assassination attempt, Commander Sinclair orders Babylon 5 sealed off until the culprit is found.
- Dr. Kyle enlists the help of Lyta Alexander to scan Kosh and determine the entry point for the toxin. This encounter is the first time a human is known to have seen a Vorlon or scanned one. After scanning Kosh, Lyta implicates Sinclair as the assassin. 
- With the information provided by Lyta, Doctor Kyle is able to determine the presence of Florazyne in Kosh's system. Unable to to find a known antidote he instead alters a similar compound to do the same job and succeeds in stabilising Kosh's condition.
- The Minbari assassin makes a second attempt on Kosh's life, this time disguised as Lyta Alexander.
- A Vorlon fleet arrives at Babylon 5 demanding the extradition of Commander Sinclair.
- Sinclair and security chief Garibaldi pursue the would-be assassin to Red 12 where he is cornered. The assassin activates a self destruct which nearly knocks the station completely off it's axis. The entire incident is transmitted via Recorders to the Vorlon fleet outside. Seeing the Minbari in a changling net they accept Sinclair's innocence and depart. 
- With Kosh fully recovered, the command staff and all of the major Ambassadors to Babylon 5 attend a formal reception in his honour. 
- Doctor Benjamin Kyle is recalled to Earth to be debriefed on his encounter with the Vorlon, though he later returns. 
- Lyta Alexander arrives on Earth and is interrogated by the Psi Corps. She says she can't put it into words and is careful to omit the fact that she has begun to feel drawn to Vorlon space. 
- Jeffrey Sinclair's relationship with Carolyn Sykes comes to an end after he refuses to resign from Earthforce and go into business with her as a trader. 
- Talia Winters hears from Jason Ironheart for the last time, prior to his arrival on Babylon 5 a year later. 
- Neeoma Connoly, the representative to the Babylon 5 Docker's Guild is promised by an EarthGov negotiator that they will be allocated additional resources in next year's budget. 
- ↑ Mind War
- ↑ A Spider in the Web
- ↑ Points of Departure
- ↑ Babylon 5: Into the Fire (Game)
- ↑ Moments of Transition
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 The Gathering
- ↑ Revelations
- ↑ In the Shadow of Z'ha'dum
- ↑ Z'ha'dum (episode)
- ↑ The Shadow Within
- ↑ 11.0 11.1 11.2 11.3 Divided Loyalties
- ↑ The Parliament of Dreams - (About a year prior to seeing Catherine Sakai again.)
- ↑ Mind War
- ↑ By Any Means Necessary
- ↑ The Passing of the Techno-Mages: Casting Shadows
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