diff --git a/ui/src/elements.tsx b/ui/src/elements.tsx
index 1f3b69b..049f929 100644
--- a/ui/src/elements.tsx
+++ b/ui/src/elements.tsx
@@ -2,7 +2,7 @@ import * as React from "react";
 import {GameWasm, Letter as LetterData, MyResult, PlayedTile, PlayerAndScore, Tray, WordResult} from "word_grid";
 import {ChangeEvent, JSX, useEffect, useMemo, useReducer, useRef, useState} from "react";
 import {Modal} from "./Modal";
-import {addNTimes} from "./utils";
+import {addNTimes, mergeTrays} from "./utils";
 
 export interface Settings {
     trayLength: number;
@@ -82,6 +82,7 @@ enum TileDispatchActionType {
     MOVE,
     RETRIEVE,
     SET_BLANK,
+    RETURN,
 }
 type TileDispatchAction = {action: TileDispatchActionType, start?: CoordinateData, end?: CoordinateData, newBlankValue?: string, blankIndex?: number};
 type TileDispatch = React.Dispatch<TileDispatchAction>;
@@ -103,49 +104,10 @@ export function Game(props: {wasm: GameWasm, settings: Settings}) {
     function movePlayableLetters(playerLetters: PlayableLetterData[], update: TileDispatchAction) {
 
         if(update.action === TileDispatchActionType.RETRIEVE) {
+
             let tray: Tray = props.wasm.get_tray("Player");
 
-
-            // we may need to check against the existing tray to retain whatever user reorderings there are
-            const freeSpots = new Array<number | null>();
-            for (let i = 0; i<props.settings.trayLength; i++) {
-                freeSpots.push(i);
-            }
-
-            playerLetters.filter((x) => {
-                return x !== undefined && x !== null;
-            }).forEach((x) => {
-                if (x.location === LocationType.TRAY) {
-                    freeSpots[x.index] = null;
-                }
-            });
-
-            const firstNotNull = (): number => {
-                for (let i of freeSpots) {
-                    if (i !== null) {
-                        freeSpots[i] = null;
-                        return i;
-                    }
-                }
-
-                return null;
-            }
-
-            // initial state
-            let letters: PlayableLetterData[] = tray.letters.map((ld, i) => {
-                if(ld !== undefined) {
-                    ld["location"] = LocationType.TRAY;
-
-                    if (playerLetters[i] !== undefined && playerLetters[i] !== null && playerLetters[i].location === LocationType.TRAY) {
-                        ld["index"] = playerLetters[i].index;
-                    } else {
-                        ld["index"] = firstNotNull();
-                    }
-                }
-                return ld as PlayableLetterData;
-            });
-
-            return letters;
+            return mergeTrays(playerLetters, tray.letters);
         } else if (update.action === TileDispatchActionType.MOVE) {
 
             let startIndex = matchCoordinate(playerLetters, update.start);
@@ -175,6 +137,8 @@ export function Game(props: {wasm: GameWasm, settings: Settings}) {
                 }
             }
             return playerLetters.slice();
+        } else if (update.action === TileDispatchActionType.RETURN) {
+            return mergeTrays(playerLetters, playerLetters);
         } else {
             console.error("Unknown tray update");
             console.error({update});
@@ -182,6 +146,8 @@ export function Game(props: {wasm: GameWasm, settings: Settings}) {
 
     }
 
+
+
     const [playerLetters, trayDispatch] = useReducer(movePlayableLetters, []);
     const [logInfo, logDispatch] = useReducer(addLogInfo, []);
 
@@ -302,6 +268,9 @@ export function Game(props: {wasm: GameWasm, settings: Settings}) {
         <button
             onClick={(e) => {setIsTileExchangeOpen(true);}}
         >Open Tile Exchange</button>
+        <button onClick={(e) => {
+            trayDispatch({action: TileDispatchActionType.RETURN});
+        }}>Return Tiles</button>
     </>;
 
 
diff --git a/ui/src/utils.ts b/ui/src/utils.ts
index bc070f3..f33640c 100644
--- a/ui/src/utils.ts
+++ b/ui/src/utils.ts
@@ -1,6 +1,52 @@
+import {Letter} from "word_grid";
+import {LocationType, PlayableLetterData} from "./elements";
 
 export function addNTimes<T>(array: T[], toAdd: T, times: number) {
     for (let i=0; i<times; i++) {
         array.push(toAdd);
     }
+}
+
+export function mergeTrays(existing: PlayableLetterData[], newer: (Letter | undefined)[]): PlayableLetterData[] {
+
+    let trayLength = Math.max(existing.length, newer.length);
+
+    // we may need to check against the existing tray to retain whatever user reorderings there are
+    const freeSpots = new Array<number | null>();
+    for (let i = 0; i<trayLength; i++) {
+        freeSpots.push(i);
+    }
+
+    existing.filter((x) => {
+        return x !== undefined && x !== null;
+    }).forEach((x) => {
+        if (x.location === LocationType.TRAY) {
+            freeSpots[x.index] = null;
+        }
+    });
+
+    const firstNotNull = (): number => {
+        for (let i of freeSpots) {
+            if (i !== null) {
+                freeSpots[i] = null;
+                return i;
+            }
+        }
+
+        return null;
+    }
+
+    return newer.map((ld, i) => {
+        if (ld !== undefined) {
+
+            if (existing[i] !== undefined && existing[i] !== null && existing[i].location === LocationType.TRAY) {
+                ld["index"] = existing[i].index;
+            } else {
+                ld["index"] = firstNotNull();
+            }
+            ld["location"] = LocationType.TRAY;
+        }
+        return ld as PlayableLetterData;
+    });
+
 }
\ No newline at end of file