Vlada Onica's "4am" is about lying awake in the dark and being unable to stop thinking about someone. The speaker says she normally dreams of whatever her mind most desires at this hour, but tonight her thoughts go to "another him," a person who seems to have taken hold of her almost effortlessly, "just by snapping his fingers." She describes him as being under her skin and in her bones, which makes the feeling sound physical and impossible to shake off.
The relationship she describes is intense and unsteady. They rarely talk, yet when they do she feels "fireworks and ending of the world" at once, thrilling and frightening in equal measure. They argue, make up, and repeat the cycle, and she calls their drama "inevitable." The mood is restless, tender and a little worn out. The last lines slow down and become plain and honest: tonight is different, and she misses him more than ever.