Yoav is telling the girls a bedtime story about why we have Lag Baomer, and how the Romans didn't allow us to do mitzvos and about how the signal fires (that we emulate with our bonfires) were so important since we didn't have email, didn't have phones, etc.
Llama: And the Romans wouldn't let the yidden have com-poo-ters.
Right, they didn't have computers. And so they used the fires because they needed to tell everyone quickly about Rosh Chodesh, and it took too long any other way.
Sroch: But they should have just gone down to the south, and up to the north, and told them.
But Srochel, they could only walk or go by horse. So it would take too long.
Sroch: So they should have gone another way!
Sroch: By rocketship.