In the first episode of Star Trek: Picard the character Dahj is attacked for a second time. During the fight it is revealed that the attackers are Romulan. Dahj fights off all the attackers, but one of them, obviously wounded, spits a green substance on Dahj and a gun she is holding. The green substance appears to be blood. It burns into Dahj's skin and also causes a (plasma?) gun she is holding to explode, killing her.

The only other green substance I know of that corrodes materials like that is the blood of the Xenomorphs from the Alien universe. Is there a connection? Coincidence? In this day and age?

I know Romulans are related to the Vulcan people. What color is their blood.

And if it was not blood but some type of bio-weapon, how could the Romulan attacker spit it without himself getting wounded?

  • I'm pretty sure that the Star Trek universe(s) is/are full enough that they don't have to cross over into the Alien franchise.
    – user62584
    Jan 31 '20 at 5:18
  • 1
    @Jeeped there has been a Star Trek / X-Men crossover - so I wouldn't rule anything out
    – HorusKol
    Jan 31 '20 at 5:49
  • 3
    In resonse to your 4th question, at least one source has looked at the frame-by-frame close enough that 'If you watch the scene, however, you can see that the acid actually reacts with his own skin just as his target.'.
    – user62584
    Jan 31 '20 at 5:58
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    No, Romulans are evolved ant-lion workers. Star Trek is in the Half-Life universe. The Computer is GlaDOS evolved. Or to be more precise, the entire experience of 24th century humans is a simulation to occupy their higher brains. Their lower brains are testing. For Science. Jan 31 '20 at 17:30
  • 1
    The assassin bites an "Acid capsule" hidden as a fake tooth. You can see that the acid starts dissolving him before dahj corrodes. It's a last resort suicidal attack.
    – DX101
    Feb 5 '20 at 13:33


Xenomorphs are part of a fictional universe created by Ridley Scott and Dan O'Bannon, and expanded upon by countless other authors.

Romulans are part of a fictional universe created by Gene Roddenberry, and expanded upon by many authors, directors and screen writers.

There is no cross-over between these universes in canon.

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