(Luther is examining the microdot Ethan found on the postcard Lindsey sent him)

It's a microdot. A microdot with nothing on it, this is unusual.

Lindsey wouldn't send me a blank microdot.

I'm telling you, man, this's no image.

Maybe you're not looking at the right place.

Well where the hell am I supposed to look? There's not much square footage to this thing.

[walking back and forth]

Why would Lindsey send me a blank microdot?

I don't know. Why would Lindsey send you anything? You were her instructor, not her handler. [Ethan turns and stares at him] Look, I don't mean to cross the line here, but was there something going on between you two? You and Lindsey?

Lindsey was like my little sister.

And you've...never slept with your little sister? [Ethan stares at him again] Look brother, if I don't ask you, who would?