Without testing, I tentatively like the duration effect. If you play it on your turn, it's a terminal attack, but your next turn starts with an extra card and an extra action (aka, Village+Laboratory). When you play it on somebody else's turn, the attack goes off, then your turn becomes just an extra action (aka, Village).
The balancing issue would then be making it actually worth it to attack while it's not your turn. If the strategically correct choice is never to play it out of turn because the Village+Laboratory effect is too good, even though it's delayed, then the entire premise of the card is defeated. During testing, the attack should prove to be better when used on somebody else's turn most of the time.
If you play it of turn, you still get the action/card?
If you play it on your turn, nothing happens but the attack, then you get the card and action on your next turn. If you play it on somebody else's turn because of the reaction, the attack happens, then you get the card and action as soon as your turn hits. So in the first scenario, the turn you play it leaves you with 4 cards and no actions left, and the second turn you have 6 cards and 2 actions. In the second scenario, you play it on someone else's turn, leaving you with 4 cards, then you draw one and get an action at the start of your turn, meaning you start your turn with 5 cards and 2 actions. In effect you get the village bonus right away at a cost of a card with your village bonus. The other redeeming feature is knowing if you have two terminals that collided, making it usually more beneficial to play when it doesn't cost you the action. On the other hand, you're less likely to need the second action if you don't use an action to get an action (like Coin of the Realm, which it's often worth losing an action to play what you have left in your hand) where you still have a chance of colliding two terminals in the next hand where you would've gotten the bigger bonus. It's a difficult point to debate, however, because sometimes it would miss the shuffle, or sometimes it's just better to have two 5-card hands than a 4- and a 6-card hand, but you can't tell until it's too late, barring Scouting Party/Cartographer.
The main reason this is more interesting than Caravan Guard is that it doesn't simply replace itself in all cases. The problem is that the attack has to be worth having one less card on the turn the duration works or else the reaction part is just flavor text.
There is also the possibility that the card was supposed to be a cantrip like Caravan Guard, but forgot to put the effect on the card, but I'm just going with it as-written.
