The Junction stations of the Solar Rail network are guarded by spectres left behind by the Orokin to safeguard the transit network. Each Junction has a list of tasks that must be completed before the Tenno can access the Junction, and then the Tenno must prevail over that Junction's guardian in order to activate the Junction and allow the Tenno to use that Solar Rail. The spectres appear to take their duty very seriously, and will attempt to kill any entity that seeks to use the Rails. Defeating them is a rite of passage for Tenno who are progressing in their journey through the Origin System.
Each Junction spectre takes the form of the warframe to be found on the destination planet of the Junction, with some exceptions. However, they all have the same dialogue lines that they will utter when the Tenno arrives.
"I am entrusted to protect this most sacred temple. A pathway into the Void. Flee or be consumed."
"Only those worthy may enter. You face certain death to oppose me."
"I have pledged my shadow-life to defend the Solar Rails."
"This sacred Rail must be protected."
"I am a Warden of the Solar Rails. I am your death."
"I am a being of the Void, created to oppose you. Leave now."
"How dare you enter my home? I guard the Rail with my shadow-life."
"Are you seeking a return to the Void? Challenge me and find destruction."
"The Solar Rails bind our System. I will not see it undone."
"Only the sacred may pass. Heathens will perish."
"Come no further if you value your life."
"Your death awaits you."
"Leave this place or be returned to the Void."
"I will purge your weakness from my Rail."
"Another intruder… another corpse for the Void."