diff --git a/loup.cabal b/loup.cabal
--- a/loup.cabal
+++ b/loup.cabal
@@ -1,5 +1,5 @@
 name:                  loup
-version:               0.0.2
+version:               0.0.3
 synopsis:              Amazon Simple Workflow Service Wrapper for Work Pools.
 description:           Loup is a wrapper around Amazon Simple Workflow Service for Work Pools.
 homepage:              https://github.com/swift-nav/loup
@@ -38,10 +38,12 @@
                      , bytestring
                      , conduit
                      , lifted-async
+                     , lifted-base
                      , monad-control
                      , preamble
                      , time
                      , turtle
+                     , unordered-containers
                      , uuid
                      , yaml
 
diff --git a/src/Network/AWS/Loup/Act.hs b/src/Network/AWS/Loup/Act.hs
--- a/src/Network/AWS/Loup/Act.hs
+++ b/src/Network/AWS/Loup/Act.hs
@@ -25,18 +25,18 @@
   pfatrs <- send $ pollForActivityTask domain list
   return (pfatrs ^. pfatrsTaskToken, pfatrs ^. pfatrsInput)
 
--- | Successful activity completion.
---
-completeActivity :: MonadAmazonCtx c m => Text -> m ()
-completeActivity token =
-  void $ send $ respondActivityTaskCompleted token
-
 -- | Cancel activity.
 --
 cancelActivity :: MonadAmazonCtx c m => Text -> m ()
 cancelActivity token =
   void $ send $ respondActivityTaskCanceled token
 
+-- | Fail activity.
+--
+failActivity :: MonadAmazonCtx c m => Text -> m ()
+failActivity token =
+  void $ send $ respondActivityTaskFailed token
+
 -- | Hearbeat.
 --
 heartbeat :: MonadAmazonCtx c m => Text -> m Bool
@@ -74,7 +74,7 @@
   intempdir $ do
     liftIO $ maybe_ input $ writeTextFile "input.json"
     stdout $ inshell command mempty
-  completeActivity token
+  failActivity token
 
 -- | Actor logic - poll for work, download artifacts, run command, upload artifacts.
 --
diff --git a/src/Network/AWS/Loup/Converge.hs b/src/Network/AWS/Loup/Converge.hs
--- a/src/Network/AWS/Loup/Converge.hs
+++ b/src/Network/AWS/Loup/Converge.hs
@@ -10,10 +10,11 @@
   ) where
 
 import Control.Monad.Trans.AWS
+import Data.HashSet             hiding (filter)
 import Data.Time.Clock.POSIX
 import Data.Yaml
 import Network.AWS.Loup.Ctx
-import Network.AWS.Loup.Prelude
+import Network.AWS.Loup.Prelude hiding (delete)
 import Network.AWS.Loup.Types
 import Network.AWS.SWF
 
@@ -48,9 +49,9 @@
 converge domain pool =
   preAmazonCtx [ "label" .= LabelDecide, "domain" .= domain, "pool" .= pool ] $ do
     let activity = pool ^. pTask ^. tActivityType
-    wids  <- listWorkflows domain activity
+    wids <- fromList <$> listWorkflows domain activity
     let fold kvs as action = do
-          let g k v bs = if k `elem` bs then return $ k `delete` bs else action k v >> return bs
+          let g k v bs = if k `member` bs then return $ k `delete` bs else action k v >> return bs
           ifoldrM g as kvs
     wids' <- fold (pool ^. pWorkers) wids $ \wid input -> do
       traceInfo "start" [ "wid" .= wid, "input" .= input ]
diff --git a/src/Network/AWS/Loup/Ctx.hs b/src/Network/AWS/Loup/Ctx.hs
--- a/src/Network/AWS/Loup/Ctx.hs
+++ b/src/Network/AWS/Loup/Ctx.hs
@@ -10,6 +10,7 @@
   , runDecisionCtx
   ) where
 
+import Control.Exception.Lifted
 import Control.Monad.Trans.AWS
 import Data.Aeson
 import Network.AWS.Loup.Prelude
@@ -23,6 +24,17 @@
   traceError "exception" [ "error" .= displayException ex ]
   throwIO ex
 
+-- | Catch TransportError's.
+--
+botErrorCatch :: MonadCtx c m => Error -> m a
+botErrorCatch ex = do
+  case ex of
+    TransportError _ ->
+      return ()
+    _ ->
+      traceError "exception" [ "error" .= displayException ex ]
+  throwIO ex
+
 -- | Catcher for exceptions, emits stats and rethrows.
 --
 topSomeExceptionCatch :: MonadStatsCtx c m => SomeException -> m a
@@ -33,7 +45,7 @@
 -- | Run bottom TransT.
 --
 runBotTransT :: (MonadMain m, HasCtx c) => c -> TransT c m a -> m a
-runBotTransT c action = runTransT c $ catch action botSomeExceptionCatch
+runBotTransT c action = runTransT c $ catches action [ Handler botErrorCatch, Handler botSomeExceptionCatch ]
 
 -- | Run top TransT.
 --
diff --git a/src/Network/AWS/Loup/Decide.hs b/src/Network/AWS/Loup/Decide.hs
--- a/src/Network/AWS/Loup/Decide.hs
+++ b/src/Network/AWS/Loup/Decide.hs
@@ -101,29 +101,22 @@
   traceInfo "completed" mempty
   return [ completeActivity ]
 
--- | Canceled workflow step.
---
-canceled :: MonadDecisionCtx c m => m [Decision]
-canceled = do
-  traceInfo "canceled" mempty
-  return [ completeActivity ]
-
--- | Timed out workflow step.
+-- | Restart workflow step.
 --
-timedout :: MonadDecisionCtx c m => m [Decision]
-timedout = do
-  traceInfo "timedout" mempty
+restart :: MonadDecisionCtx c m => m [Decision]
+restart = do
+  traceInfo "restart" mempty
   uid   <- liftIO nextRandom
   task  <- view pActivityTask <$> view dcPlan
   event <- findEvent WorkflowExecutionStarted
   let input = join $ view weseaInput <$> join (view heWorkflowExecutionStartedEventAttributes <$> event)
   return [ scheduleActivity uid (task ^. tActivityType) (task ^. tTaskList) input ]
 
--- | Failed workflow step.
+-- | Cancel failed workflow step.
 --
-failed :: MonadDecisionCtx c m => m [Decision]
-failed = do
-  traceInfo "failed" mempty
+canceled :: MonadDecisionCtx c m => m [Decision]
+canceled = do
+  traceInfo "canceled" mempty
   return [ cancelActivity ]
 
 -- | Schedule decision based on history events.
@@ -136,9 +129,10 @@
         | e ^. heEventType == WorkflowExecutionStarted         = begin e
         | e ^. heEventType == WorkflowExecutionCancelRequested = cancel
         | e ^. heEventType == ActivityTaskCompleted            = completed
-        | e ^. heEventType == ActivityTaskCanceled             = canceled
-        | e ^. heEventType == ActivityTaskTimedOut             = timedout
-        | e ^. heEventType == RequestCancelActivityTaskFailed  = failed
+        | e ^. heEventType == ActivityTaskCanceled             = completed
+        | e ^. heEventType == ActivityTaskTimedOut             = restart
+        | e ^. heEventType == ActivityTaskFailed               = restart
+        | e ^. heEventType == RequestCancelActivityTaskFailed  = canceled
         | otherwise                                            = f es
   events <- view dcEvents
   f events