Seek Horizon (Yellow)

As an additional cost to play this, you may put a card from your hand on top of your deck.

If the additional cost was paid, this gets go again.

Rulings

From the Monarch release notes

You cannot pay its additional cost if you have no cards in hand.
You cannot pay its additional cost by putting Seek Horizon on top of your deck.
You cannot put more than one card on top of your deck with its additional cost.

Keyword notes

Go again - Go again allows multiple actions to be played in a turn when usually playing an action with use up your action point, and therefore end your turn. A card with go again gives the controller of that card or activated ability 1 action point when it resolves.

When an action with go again resolves, its controller gains 1 action point.
Multiple instances of go again on the same card or activated ability do not stack. If a card or activated ability has multiple instances of go again when it resolves its controller gains 1 action point only.
If an action with go again does not resolve, its controller does not gain 1 action point.
You cannot reveal a card with no to Belittle. The card must have a value to its power that is 3 or less. (0 is a value)