This is how Megatron and Dreadwing find Starscream and his minions on the Nemesis goes in Inside Job.
[On the Nemesis, Knock Out is still jammed in the wall]
Knock Out: I beg you, my liege, release me from this absurd predicament!
Megatron: No! You shall serve as a constant reminder to those who dare fail me.
[Megatron and Dreadwing leave]
[They enter the bridge]
Megatron: I cannot allow Optimus Prime to be the one to revive Cybertron. We will locate the Autobot base, invade it, and retrieve the Omega keys.
Starscream: Been there, done that.
[They look around]
[Megatron looks up and sees Starscream and his minions]
Starscream: Please pardon our unannounced visit, Lord Megatron.
Nightmare Moon: We may not be welcome.
Tirek: But we have something to show you.
Adagio Dazzle: Something even you couldn't retrieve.
Aria Blaze: That's right.
Sonata Dusk: No need for invasion.
Tempest Shadow: Yeah.
Queen Chrysalis: We've got what you want.
King Sombra: Exactly.
[Dreadwing prepares to attack when Megatron stops him]
Starscream: But we have come bearing a peace offering.
Nightmare Moon: The Omega Keys.
Tirek: Ones you've been after.
Adagio Dazzle: We've collected all four.
Aria Blaze: Just like you wanted.
Sonata Dusk: And we will do well.
Tempest Shadow: If you give us one opportunity.
Queen Chrysalis: That's right.
King Sombra: Let us explain.
[Starscream presents the keys and the episode ends]