Very rough draft (aerth):

alice and bob find escrow parties that have more aqua than the tx is worth. need X number of them, from each team. need 2/3 able (no even numbers)

alice puts aqua in the contract, tells bob and the escrow panel the contract

contract has something like Asking() which returns an exact btc amount for the total package , Amount()

so me you and joe are escrow panel and sign up by putting that amount in the contract in a separate function, like Help() with any amount higher than Amount() returns

alice has put in 10 aqua, asking 1 btc.

bob and alice advertise the contract somehow (maybe a decentralized exchange of sorts)

escrow panel fills up , people put in 10 aqua to be part of it.

so me u and joe put 10 aqua in, and so did alice.

bob sends his btc. knowing its now safe

me you and joe receive the tx hash from bob, we insert it into the contract

alice just got bob's btc, her aqua is still in the contract

since me u and joe agree on the same tx hash, we get our aqua back.

alice's aqua gets released to bob.

me you and joe got a little extra for participating honestly