Can hide in plain sight, melee, spring attack, hide work together?

Question

My character has recently obtained the ability to hide in plain sight. And I am having trouble understanding how it all works. So if my character is hiding (using the hide in plain sight ability). And then moves, performs a melee attack on a foe, and then moves away to hide in plain sight again, does it work?

My understanding is:

Hide in plain sight is a supernatural ability, and therefore it takes no action : see Do special abilities require an action every round they are active?

Spring attack allows me to move, then attack, and then move.

The hide skill ability can be a part of a move action :

Usually none. Normally, you make a Hide check as part of movement, so it doesn’t take a separate action. However, hiding immediately after a ranged attack (see Sniping, above) is a move action.

Is the above all possible?

My other question is, while my character is moving and attacking, is he still hidden, or is he only hidden after the move is completed?

Will the foe know which square my character ended in?

Answer 1

It’s practically impossible (-20 penalty) to hide while attacking, running or charging.

So you can remain hidden while making a spring attack, but the DC to spot you is not going to be very high. If you still manage to win the opposed roll, your target will be denied its Dexterity bonus to AC and will have an additional -2 penalty because you are effectively invisible.

From Skip Williams' column:

If a foe you cannot see hits you with a melee attack and is adjacent to you at the time, you know the foe's location. For this reason, smart foes move right after they attack; even a foe that has made a full attack can move after attacking by taking 5-foot step (provided it has not already moved during its turn).

When an unseen foe hits you with a melee attack from more than 5 feet away, you know the general direction from which the attack came and that the attack came from more than 5 feet away, but you do not know the attacker's location.

That is the main reason to spring attack: you need to move after attacking, even if invisible, otherwise your target will know your location. If your target has failed its spot check, you still have total concealment (50% miss chance).

Answer 2

My read (and this would be based on the rules for the invisibility spell):

• You are waiting your turn hiding. Status: Hidden
• You move to the target. Status: Hidden, but I'd give the target a roll to see someone sneaking up on him (if coming from the front)
• You get all stabby with your knife. Status: NOT Hidden.
• You move away using Spring Attack. Status: Not Hidden.
• You get to your safe place and hide. Status: Hidden
• You repeat this process. Status: Hidden as above, but you don't get the back-stab bonus.

I'd take away the bonus because he knows you are back there, but is more worried about the fighter cutting him into ribbons if he turns around to look at you, but his mind is also trying to find spots that he can defend from both attack vectors. I am away from my books so I don't know if there is an "attacking from cover" or similar bonus, but I'd give that (or half of that) due to you being hidden, but known to the target.