local function Chain_OnUpdate(self, elapsed)
    if (self.chainPause) then
        return;
    end

    local rev = self.chainRev;
    local e = self.chainElapsed + elapsed;
    self.chainElapsed = e;

    local points = 3;
    local off = {self.chainY+20, -30, 10};
    local dur = {self.chainY/400, 0.2, 0.3};

    local tDur = 0;
    for i = 1, points do
        tDur = tDur + dur[i];
    end

    e = math.min(e, tDur);
    if (rev) then
        e = math.max(0, tDur - e);
    end

    local aDur = 0;
    local y = -10;

    if (e > 0) then
        for i = 1, points do
            if (e < aDur + dur[i]) then
                y = y + off[i] * ((e - aDur) / dur[i]);
                pause = false;
                break;
            else
                y = y + off[i];
            end
            aDur = aDur + dur[i];
        end
    end

    self:SetPoint("BOTTOMLEFT", UIParent, "TOPLEFT", self:GetLeft(), -y);

    if ((rev and e == 0) or (not rev and e == tDur)) then
        self.chainRev = not rev;
        self.chainPause = true;
        self.chainElapsed = 0;
    end
end